When I was chanting today. I remember this advice given in most Japa Seminars. The advice is very sound – just hear the present mantra you are chanting….focus on one mantra at a time and be in the present with it – absorb the sound into yourself and feel the Lord's spiritual energy.
By giving respect to the Hare Krsna mantra….respect that comes from pronouncing and hearing with attention….then Krsna accepts that devotion and reciprocates. He reciprocates by giving us drops of spiritual energy and purification by His association through the Holy Names.