One should accept the following principles to properly execute devotional service:
(1) Take shelter of a bona fide spiritual master.
(2) Receive initiation from the spiritual master.
(3) Serve the spiritual master.
(4) Inquire and learn love from the spiritual master.
(5) Follow in the footsteps of holy persons devoted to the transcendental loving service of the Lord.
(6) Prepare to give up all kinds of enjoyment and miseries for the satisfaction of Krishna.
(7) Live in a place where Krishna had His pastimes.
(8) Be satisfied by whatever is sent by Krishna for the maintenance of the body and hanker for no more.
(9) Observe fasting on Ekadasi day (this occurs on the eleventh day after the full moon and the eleventh day after the new moon. On such days no grains, cereals or beans are eaten; simply vegetables and milk are moderately taken, and chanting Hare Krishna and reading scriptures are increased).
(10) Show respect to devotees, cows and sacred trees like a banyan tree.
It is essential for a neophyte devotee who is beginning to follow the path of devotional service to observe these ten principles.
Source: A.C. Bhaktivedanta Swami Prabhupada (2012 edition), “Teachings of Lord Caitanya, The Golden Avatara”, Page 143