Tapping the meter consists of tapping on the strong beats. Following is a list of common meters and their metrical emphasis:
- 4/4, tap on 1 and 3
- 3/4, tap on 1
- 6/8, tap on the dotted quarter note
- 5/4 (most typical), tap on 1 and 4
- 7/4 (most typical), tap on 1, 3, and 5, though I also usually add one more tap on the "and" of 6 or 7 depending on the line
Recently I've learned that meter is processed by the right side of the brain. Considering the right brain controls the left side of the body, a possible conclusion is that it would be more natural to tap the meter with the left foot. I've found this to be the case. Tapping the meter with my left foot, particularly when I could use the reinforcement like in an odd time signature, helps my improvisation sound better, more fluid and interesting. Give it a shot, and leave a comment if you find it helpful.