In Srimad-Bhagavatam, Vedavyasa Muni has said:

sravanam kirtanam dhyanam
harer adbhuta-karmanah
janma-karma- gunanam ca
tad-arthe 'khila-cestitam
(Srimad-Bhagavatam, 11.3.27)

Vedavyasa Muni gave instruction that you should hear about Sri Hari (sravanam): the name, form, attributes and pastimes of Sri Hari, about His advent in this world, about His transcendental divine qualities and about His transcendental pastimes. You have to hear this from a bona fide pure devotee and not from a platform speaker - those who speak for some worldly benefit. If you hear from them, you will not be benefited. Their motive is different. You are to associate with bona fide devotees - those who have sacrificed and dedicated their lives for the service of Sri Krishna alone, and who have no ulterior motive behind them. When you hear from such devotees then your mind will go to Sri Krishna. Having heard, you should repeat it, you should chant whatever you have heard. Chant (kirtanam). First you engage your ears in the service of Sri Krishna and then you engage your tongue in the service of Sri Krishna by speaking about Sri Krishna, whatever you have heard. You should not say anything of your own creation, as you will not get the actual benefit. Try to remember whatever you have heard from suddha-bhaktas (pure devotees) and bona fide gurus and pray for their grace. By their grace alone will you be able to speak - only by the grace of Guru-Vaisnava-Bhagavan. You cannot serve them without their grace. Service is not accomplished by means of mundane vanity. You should not deliver a speech at a public meeting to obtain respect from the audience. That is not your target. Your target is to engage your senses and the objects of the sense organs in the service of Sri Krishna. Wherever we engage our senses, wherever we engage the objects of our senses, there we shall go. If we engage our sense organs, our mind and intellect (both gross and subtle senses) for worldly things, we will become attached to worldly things. If we engage the same for the service of Sri Krishna and His devotees, we will become attached to Sri Krishna and His devotees. So with that aim, with that target, you are to speak for the satisfaction of Sri Krishna and His devotees. Try to do this, by praying for the grace of Guru-Bhagavan. Wherever I go, I try to do this, although I have many frailties and drawbacks. To those who help me in this manner, I am grateful.