To get more points on a clapping drum roll, just whistle through it. I pretty sure Kong can't clap faster then that.
On the title screen, you can make the "Press Start" text move by clapping. The "P" in "Press" picks up the more quiet clapping sounds as the "t" in "Start" picks up louder clapping sounds. The Letters in between pick up average rate claps. It acts like a volume graph on a stereo or PC Media player.
Tap both LEFT and RIGHT simultaneously when yellow or red drums appear to make sure of the hit. This may physically destroy your controller or accelerate its wear.
Some sound sets you that you can buy at Bongos-a-go in DK Town are suitable with certain songs. Here is a list of them: