1. The preaching style ISKCON devotees must adopt

    The members of the Krsna consciousness movement chant a minimum of sixteen rounds a day, which can be done without difficulty, and at the same time they must preach the cult of Caitanya Mahaprabhu according to the gospel of Bhagavad-gita As It Is. One who does so is quite fit to become a spiritual master for the entire world.

    From Srila Prabhupada’s purport to Cc Antya 4.103