Scales, chords, arpeggios, reviewing some favourites, work on your new pieces, sight reading, ear training, and for jazz musicians there is alway transcribing. Whew! Sometimes it is all a bit much. Sometimes the best use of a hour is just too...
You've got to learn your instrument. Then, you practice, practice, practice. And then, when you finally get up there on the bandstand, forget all that and just wail.
I'm a professional pianist and music educator in West Toronto Ontario. I'm also a devoted percussionist and drum teacher.