Chanting of the Hare Krsna mantra is the easiest process of meditation in this age. As soon as one chants the Hare Krsna mantra, he sees the forms of Krsna, Rama and Their energies, and that is the perfect stage of trance. One should not artificially try to see the form of the Lord while chanting Hare Krsna, but when the chanting is performed offenselessly the Lord will automatically reveal Himself to the view of the chanter. The chanter, therefore, has to concentrate on hearing the vibration, and without extra endeavor on his part, the Lord will automatically appear.

From Srila Prabhupada’s purport to SB 4.8.53