This could work as either an opening or a closing rhyme, although I've been using it as my closer (just substitute "Hello" for "Goodbye" at the end).
Our hands say thank you with A clap, clap, clap;
Our feet say thank you with a
Tap, tap, tap.
Clap, clap, clap!
Tap, tap, tap!
We roll our hands around, and say,
“Good-bye.”