I practice mainly in up to 2 sessions a day of: [3 sets x 3 exercises x 3 minutes], I have an ‘exercise bank’ and I choose my exercises from it (also if I did 1 exercise in yesterday’s night, I’d probably repeat it in the morning session), also in addition to that I play few times some of the exercises in the bank.
When should I switch exercises, after each 2 days or 1 day? OR switch exercises only after I ‘perfect’ them (play them good enough for my current level/standards)?
(the exercises I pick are mainly parts of musical composition that work on some specific technical mistakes I have)