The best way is to hear yourself chanting the actual names, Hare Krsna mantra. This is the way to chant without losing attention. One’s mind should be fixed on the sound. As Prabhupada has written, the mouth should move. One should not slur Hare Krsna, Hare Krsna. He should not fall asleep while chanting in his so-called bhajana. As Krsna advises Arjuna in practicing yoga, “Wherever the mind wanders due to its restless and flickering nature, you have to drag it back.” So this applies to our chanting. You have to chant with attention. Remain awake and chant with devotion.