Everything depends on practice. Abhyāsa-yoga-yuktena cetasā nānya-gāminā (B.G.8:8). Everything we acquire by spiritual practice.
(Lecture on Srimad Bhagavatam------5:5:2-------by Srila Prabhupada).

So from the beginning we have to practice Kṛṣṇa consciousness if we are actually serious to go back to home, back to Godhead. Not that let it be left for two or three years before death.
(Lecture on Bhagavad-Gita------1:28-29------by Srila Prabhupada).

One has to take advantage of this knowledge and mold his life in such a way that at the end, especially in the human form of life, he may go back home, back to Godhead, by practicing Kṛṣṇa consciousness.
(Srimad Bhagavatam------4:21:27------purport).

But one who has purified his mind and senses by practicing Kṛṣṇa consciousness in devotional service can see Him constantly. It is confirmed in Brahma-saṁhitā that the devotee who has developed love for the Supreme God can see Him always, without cessation.
(Bhagavad-Gita------13:16------purport).

In his Anuvṛtti explanation of Upadeśāmṛta, Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura writes that our material identification creates three kinds of urges—the urge to speak, the urge or demands of the mind and the demands of the body. When a living entity falls victim to these three types of urges, his life becomes inauspicious. One who practices resisting these demands or urges is called tapasvī, or one who practices austerities. By such tapasya one can overcome victimization by the material energy, the external potency of the Supreme Personality of Godhead.
(Nectar of Instruction).

Ordinary men are therefore advised to concentrate the mind by focusing on the place between the eyebrows, whereas the devotees of the Lord are already practiced to place the Supreme Personality of Godhead on the seat of their minds.
(Srimad Bhagavatam------3:12:26------purport).

Practice means employing our senses in some particular type of work. Therefore devotional service in practice means utilizing our different sensory organs in service to Kṛṣṇa. Some of the senses are meant for acquiring knowledge, and some are meant for executing the conclusions of our thinking, feeling and willing. So practice means employing both the mind and the senses in practical devotional service. This practice is not for developing something artificial. For example, a child learns or practices to walk. This walking is not unnatural. The walking capacity is there originally in the child, and simply by a little practice he walks very nicely. Similarly, devotional service to the Supreme Lord is the natural instinct of every living entity. Even uncivilized men like the aborigines offer their respectful obeisances to something wonderful exhibited by nature's law, and they appreciate that behind some wonderful exhibition or action there is something supreme. So this consciousness, though lying dormant in those who are materially contaminated, is found in every living entity. And, when purified, this is called Kṛṣṇa consciousness.
(Nectar of Devotion).

Practice of austerity is the main business of human life.
(Srimad Bhagavatam------4:9:67------purport).

Therefore, although He is present in every atom, the Supreme Personality of Godhead may not be visible to the dry speculators; still the mystery is unfolded before the eyes of the pure devotees because their eyes are anointed with love of Godhead. And this love of Godhead can be attained only by the practice of transcendental loving service of the Lord, and nothing else.
(Srimad Bhagavatam------2:9:35------purport).

The real purpose of yoga practice is to achieve the highest perfection of Kṛṣṇa consciousness, as explained in the last verse of this chapter. But those who do not persevere to such an extent and who fail because of material allurements are allowed, by the grace of the Lord, to make full utilization of their material propensities. And after that, they are given opportunities to live prosperous lives in righteous or aristocratic families. Those who are born in such families may take advantage of the facilities and try to elevate themselves to full Kṛṣṇa consciousness.
(Bhagavad-Gita------6:41------purport).

The approved method for understanding the Supreme Personality of Godhead, Kṛṣṇa, is the path of devotional service, and this is confirmed in every Vedic scripture. Devotional service of the Lord begins by hearing about Him. There are nine different methods in devotional service, of which hearing is the chief. Hearing, chanting remembering, worshiping—all these are used in the process of attaining the highest perfection by understanding the Supreme Personality of Godhead. This process by which the Supreme Personality of Godhead is understood is known as abhidheya, practice of devotional service within conditional life.
(Teachings of Lord Caitanya).

It is not possible for the Brahman-realized impersonalist or the Paramātmā-realized yogī to understand Kṛṣṇa, the Supreme Personality of Godhead as the son of mother Yaśodā or the charioteer of Arjuna. Even the great demigods are sometimes confused about Kṛṣṇa (muhyanti yat sūrayaḥ). Māṁ tu veda na kaścana: "No one knows Me as I am," the Lord says. And if one does know Him, then sa mahātmā su-durlabhaḥ. "Such a great soul is very rare." Therefore unless one practices devotional service to the Lord, one cannot know Kṛṣṇa as He is (tattvataḥ), even though one is a great scholar or philosopher. Only the pure devotees can know something of the inconceivable transcendental qualities in Kṛṣṇa—His being the cause of all causes, His omnipotence and opulence, and His wealth, fame, strength, beauty, knowledge and renunciation—because Kṛṣṇa is benevolently inclined to His devotees. He is the last word in Brahman realization, and the devotees alone can realize Him as He is.
(Bhagavad-Gita------7:3------purport).

1. The serious candidate must accept a bona fide spiritual master in order to be trained scientifically. Because the senses are material, it is not at all possible to realize the Transcendence by them. Therefore the senses have to be spiritualized by the prescribed method under the direction of the spiritual master.
2. When the student has chosen a bona fide spiritual master, he must take the proper initiation from him. This marks the beginning of spiritual training.
3. The candidate must be prepared to satisfy the spiritual master in every way. A bona fide spiritual master who is fully cognizant of the methods of spiritual science, learned in the spiritual scriptures such as the Bhagavad-gītā, Vedānta, Śrīmad-Bhāgavatam and Upaniṣads, and who is also a realized soul who has made a tangible connection with the Supreme Lord, is the transparent medium by which the willing candidate is led to the path of the Vaikuṇṭhas. The spiritual master must be satisfied in all respects, because simply by his good wishes a candidate can make wonderful progress along the path.
4. The intelligent candidate places intelligent questions to the spiritual master in order to clear his path of all uncertainties. The spiritual master shows the way, not whimsically, but in accordance with the principles of the authorities who have actually traversed the path. The names of these authorities are disclosed in the scriptures, and one has simply to follow them under the direction of the spiritual master. The spiritual master never deviates from the path of the authorities.
5. The candidate should always try to follow in the footsteps of the great sages who have practiced the method and obtained success. This should be taken as a motto in life. One should not superficially imitate them, but should follow them sincerely in terms of the particular time and circumstances.
6. The candidate must be prepared to change his habits in terms of the instructions contained in the books of authority, and for the satisfaction of the Lord he must be prepared to sacrifice both sense gratification and sense abnegation, following the example of Arjuna.
7. The candidate should live in a spiritual atmosphere.
8. He must be satisfied with as much wealth as is sufficient for maintenance only. He should not try to amass more wealth than is necessary to sustain himself in a simple way.
9. He must observe the fasting dates, such as the eleventh day of the growing and waning moon.
10. He must show respect to the banyan tree, the cow, the learned brāhmaṇa and the devotee.
These are the first stepping-stones toward the path of devotional service. Gradually one has to adopt other items, which are negative in character:
11. One should avoid offenses in the discharge of devotional service and in chanting the holy names.
12. He should avoid extensive association with nondevotees.
13. He must not take on unlimited disciples. This means that a candidate who has successfully followed the first twelve items can also become a spiritual master himself, just as a student becomes a monitor in class with a limited number of disciples.
14. He must not pose himself as a vastly learned man simply by quoting statements in books. He must have solid knowledge of the necessary books without superfluous knowledge in others.
15. A regular and successful practice of the above fourteen items will enable the candidate to maintain mental equilibrium even amidst great trials of material loss and gain.
16. In the next stage, the candidate does not become afflicted by lamentation and illusion.
17. He does not deride another's mode of religion or worship, nor does he deride the Personality of Godhead or His devotees.
18. He never tolerates blasphemy against the Lord or His devotees.
19. He should not indulge in the discussion of topics dealing with the relationship between man and woman; nor should he engage in useless topics concerning others' family affairs.
20. He should not inflict pain—either in body or in mind—upon other living beings, whomsoever they may be.
Out of the above twenty items, the first three positive items are imperative and most essential for the serious candidate.
There are forty-four other items to be followed by the serious candidate, but Lord Caitanya has selected five as the most important. These were selected owing to the present conditions of civic life. They are as follows:
1. One should associate with the devotees. Association with devotees is made possible by hearing them attentively, by asking them relevant questions, by supplying them food and by accepting food from them, and by giving them charity and by accepting from them whatever they offer.
2. One should chant the holy name of the Lord in all circumstances. The chanting of the Lord's name is an easy and inexpensive process of realization. One can chant any of the innumerable names of the Lord at any time. One should try to avoid offenses. There are ten offenses which one can commit while chanting the transcendental names, and these should be avoided as far as possible, but in any event, one should try to chant the holy names of the Lord at all times.
3. One should hear the transcendental topics enunciated in the Śrīmad-Bhāgavatam. This hearing is made possible through platform lectures by bona fide devotees and by authorized translations of the Bhāgavatam.
4. One should make his home at Mathurā, the birthplace of Lord Kṛṣṇa. Or one may make his home as good as Mathurā by installing the Deity of the Lord to be worshiped by all members of the family after proper initiation from the spiritual master.
5. One should worship the installed Deity with attention and devotion so that the whole atmosphere of one's home becomes the replica of the Lord's abode. This is made possible by the direction of the spiritual master who knows the transcendental art and can show the candidate the proper method.
(Easy journey to other Planets).

The practice of yoga is concisely explained herein. When this practice of yoga is perfect, one sees the Supersoul, the Paramātmā feature of the Supreme Personality of Godhead, within the core of one's heart. However, in Bhagavad-gītā (6.47) the Supreme Lord says:
yoginām api sarveṣām
mad-gatenāntarātmanā
śraddhāvān bhajate yo māṁ
sa me yuktatamo mataḥ
"Of all yogīs, he who always abides in Me with great faith, worshiping Me in transcendental loving service, is most intimately united with Me in yoga and is the highest of all." A devotee can immediately become a perfect yogī because he practices keeping Kṛṣṇa constantly within the core of his heart. This is another way to practice yoga easily. The Lord says:
man-manā bhava mad-bhakto
mad-yājī māṁ namaskuru
"Always think of Me and become My devotee. Worship Me and offer your homage unto Me." (B.G.18:65) If one practices devotional service by always keeping Kṛṣṇa within the core of his heart (man-manāḥ), he immediately becomes a first-class yogī. Furthermore, keeping Kṛṣṇa within the mind is not a difficult task for the devotee. For an ordinary man in the bodily concept of life, the practice of yoga may be helpful, but one who immediately takes to devotional service can immediately become a perfect yogī without difficulty.
(Srimad Bhagavatam------7:15:32-33------purport).

In the Brahma-saṁhitā (5.44) there is this statement:
sṛṣṭi-sthiti-pralaya-sādhana-śaktir ekā
chāyeva yasya bhuvanāni bibharti durgā
The māyā-śakti, Durgā, is in charge of sṛṣṭi-sthiti-pralaya, creation and dissolution, and she acts under the direction of the Supreme Lord (mayādhyakṣeṇa prakṛtiḥ sūyate sa-carācaram (B.G.9:10). When one falls in the river of nescience, he is always tossed here and there by the waves, but the same māyā can also save him when be surrenders to Kṛṣṇa, or becomes Kṛṣṇa conscious. Kṛṣṇa consciousness is knowledge and austerity. A Kṛṣṇa conscious person takes knowledge from the Vedic literature, and at the same time he must practice austerities.
(Srimad Bhagavatam------6:5:16------purport).

To give charity is one of the householder's main functions, and he should be prepared to give in charity at least fifty percent of his hard-earned money. A brahmacārī, or student, should perform sacrifices, a householder should give charity, and a person in the retired life or in the renounced order should practice penances and austerities. Those are the general functions of all the āśramas, or orders of life on the path of self-realization. In the brahmacārī life the training is sufficiently imparted so that one may understand that the world as property belongs to the Supreme Lord, the Personality of Godhead. No one, therefore, can claim to be the proprietor of anything in the world. Therefore, in the life of a householder, which is a sort of license for sex enjoyment, one must give in charity for the service of the Lord. Everyone's energy is generated or borrowed from the reservoir of energy of the Lord; therefore, the resultant actions of such energy must be given to the Lord in the shape of transcendental loving service for Him. As the rivers draw water from the sea through the clouds and again go down to the sea, similarly our energy is borrowed from the supreme source, the Lord's energy, and it must return to the Lord. That is the perfection of our energy. The Lord, therefore, in the Bhagavad-gītā (9.27) says that whatever we do, whatever we undergo as penance, whatever we sacrifice, whatever we eat or whatever we give in charity must be offered to Him (the Lord). That is the way of utilizing our borrowed energy. When our energy is utilized in that way, our energy is purified from the contamination of material inebrieties, and thus we become fit for our original natural life of service to the Lord.
(Srimad Bhagavatam------1:9:27------purport).

A devotee engaged in chanting the holy name of the Lord should practice forbearance like that of a tree. Even if rebuked or chastised, he should not say anything to others to retaliate.
(Sri Caitanya Caritamrta-----1:17:27------purport).

A first-class brāhmaṇa does not accept any rewards from his disciples or yajamānas. Practicing austerities and penances, he instead goes to the agricultural field and collects food grains left by the agriculturalists to be collected by brāhmaṇas. Similarly, such brāhmaṇas go to marketplaces where grains are purchased and sold wholesale, and there they collect grains left by the merchants. In this way, such exalted brāhmaṇas maintain their bodies and families. Such priests never demand anything from their disciples to live in opulence, imitating kṣatriyas or vaiśyas. In other words, a pure brāhmaṇa voluntarily accepts a life of poverty and lives in complete dependence on the mercy of the Lord. Not very many years ago, a brāhmaṇa in Kṛṣṇanagara, near Navadvīpa, was offered some help from the local Zamindar, Rājā Kṛṣṇacandra. The brāhmaṇa refused to accept the help. He said that since he was very happy in his householder life, taking rice given by his disciples and cooking vegetables of tamarind leaves, there was no question of taking help from the Zamindar. The conclusion is that although a brāhmaṇa may receive much opulence from his disciples, he should not utilize the rewards of his priesthood for his personal benefit; he must use them for the service of the Supreme Personality of Godhead.
(Srimad Bhagavatam------6:7:36------purport).

Tapas, or austerity, is especially meant for the retired life. One should not remain a householder throughout his whole life; he must always remember that there are four divisions of life—brahmacarya, gṛhastha, vānaprastha and sannyāsa. So after gṛhastha, householder life, one should retire. If one lives for a hundred years, he should spend twenty—five years in student life, twenty-five in householder life, twenty-five in retired life and twenty-five in the renounced order of life. These are the regulations of the Vedic religious discipline. A man retired from household life must practice austerities of the body, mind and tongue. That is tapasya. The entire varṇāśrama-dharma society is meant for tapasya. Without tapasya, or austerity, no human being can get liberation. The theory that there is no need of austerity in life, that one can go on speculating and everything will be nice, is recommended neither in the Vedic literature nor in Bhagavad-gītā. Such theories are manufactured by show-bottle spiritualists who are trying to gather more followers. If there are restrictions, rules and regulations, people will not become attracted. Therefore those who want followers in the name of religion, just to have a show only, don't restrict the lives of their students, nor their own lives. But that method is not approved by the Vedas.
(Bhagavad-Gita------16:1-3------purport).

By practice, one should avoid eating in such a way that other living entities will be disturbed and suffer. Since I suffer when pinched or killed by others, I should not attempt to pinch or kill any other living entity. People do not know that because of killing innocent animals they themselves will have to suffer severe reactions from material nature. Any country where people indulge in unnecessary killing of animals will have to suffer from wars and pestilence imposed by material nature. Comparing one's own suffering to the suffering of others, therefore, one should be kind to all living entities. One cannot avoid the sufferings inflicted by providence, and therefore when suffering comes one should fully absorb oneself in chanting the Hare Kṛṣṇa mantra. One can avoid sufferings from the body and mind by practicing mystic haṭha-yoga.
(Srimad Bhagavatam------7:15:24------purport).

The six symptoms of fully surrendered souls are also described in this chapter. Devotional service has been divided into two categories-regulative devotional service and spontaneous love. There are sixty-four items listed in regulative devotional service, and out of these sixty-four the last five are considered very important. By practicing even one of the nine processes of devotional service, one can become successful. Speculative knowledge and mystic yoga can never help one in devotional service. Pious activity, nonviolence, sense control and regulation are not separate from devotional service in its pure form. If one engages in devotional service, all good qualities follow. One does not have to cultivate them separately. Spontaneous devotional service arises when one follows a pure devotee who is awakened to spontaneous love of God. Śrī Caitanya Mahāprabhu describes the symptoms of devotees who are already situated in spontaneous love of God. He also describes the devotees who are trying to follow in the footsteps of the pure devotees.
(Sri Caitanya Caritamrta------2:22------summary).

One may very easily practice chanting and hearing the holy name of the Lord and thus become ecstatic in spiritual life. Padma Purāṇa states:
nāmāparādha-yuktānāṁ
nāmāny eva haranty agham
aviśrānti-prayuktāni
tāny evārtha-karāṇi ca
Even if one chants the Hare Kṛṣṇa mahā-mantra offensively, one can avoid offenses by continuously chanting without deviation. One who becomes accustomed to this practice will always remain in a pure transcendental position, untouchable by sinful reactions. Śukadeva Gosvāmī especially requested King Parīkṣit to note this fact very carefully. There is no profit, however, in executing the Vedic ritualistic ceremonies. By performing such activities one may go to the higher planetary systems, but as stated in Bhagavad-gītā (9.21), kṣīṇe puṇye martya-lokaṁ viśanti: when the period of one's enjoyment in the heavenly planets is terminated because of the limited extent of the results of one's pious activities, one must return to earth. Thus there is no use in endeavoring to travel up and down in the universe. It is better to chant the holy name of the Lord so that one may become fully purified and eligible to return home, back to Godhead. That is the aim of life, and that is the perfection of life.
(Srimad Bhagavatam------6:3:32------purport).