Are you working out for boxing or to be in shape? I didn't see mention of how long you've boxed or anything and it doesn't sound like you're working in a gym with a coach.

How are you working the bag? You said something about jabbing and reseting but I'm not sure what you mean by resetting and if you're going straight through your 25 or however many minutes doing the same thing with no breaks. If you're looking to get into boxing I'd recommend going to a round system on the bag (and for other things like skipping,etc) where you do 2-3 minutes hard activity and 30 seconds to 1 minute resting. If you know how to properly throw the punches you can vary working on combinations, speed, power. If not maybe stick with jabs and crosses and you may want to get some instruction before doing too much so you don't end up developing bad habits.