I have regressed I to treating myself like a toddler, using sleep as the ultimate motivator. I make deals with myself. Like, if I read ten pages of my psych textbook, I earn myself 10 minutes of napping. Bigger assignments equal longer amounts. An online quiz is 20 minutes and a four page paper is worth an hour. (Getting to all of my classes for the day is 20 minutes all by itself.) An hour of piano practice is 30 minutes and resisting the urge to scream out loud during Short Story varies depending on how stupid the class was on any given day.
I think it's a pretty brilliant system.