Not sure about this...When you are ptacticing on the heavy bag, jab/right/hook is your bread and butter because that is the basis of every thing else. I also like a left uppercut/right/hook or left uppercut/left hook/right...but remembering them? On the bag you should be testing and perfecting your balance and technique, so just let them flow and be checking yourself to improve. Remembering or practicing a few sequences will leave you stuck for ideas later on.
Because, when you are fighting somebody, you can't just work certain sequences. Suppose he jabs and pulls his right hand ( I always assume an orthodox stance because I believe all southpaws should have been drowned at birth) back as he does so: the obvious counter is to slip outside and hook, but what then? Do you see what I am getting at? You have to prepare yourself for anything, not memorize routines.