One of my adult students was asking tonight for some help planning his practice time. He is preparing for his Grade 8 piano exam. He is an engineer, a spreadsheet kind of guy. I'm sympathetic. Here is what we discussed.
Warmup with sight reading. Use a metronome! Get into the zone.
Now start practicing
Technique with a 2-minute timer. Switch activities every 2 minutes = 15 minutes
Practice one short section to perfection =15 minutes
Theory =10 minutes
Ear Training = 10 minutes
Review completed piece or pieces 10 minutes
BOOM! one hour of accomplishment
This may work for you.
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.