Some people use yoga, some use a mantra, some prefer self flagellation; I have found that you can get there through watching a clay pot form from a cold wet lump of earth on a spinning wheel. You can definitely get there through the focus necessary to play music. But the method I find the most enjoyable is juggling. Get into the pattern, be the ball, feel the beat, the rhythm, the meter, the repetition, the syncopation, the sequence, the ...