rewards/consequences is part of it. For example, if I do well on a test, it will help me to get a good grade, which will help my GPA. Having a good GPA can help you land a better job out of school (I've heard it doesn't matter after your first real job), which will set you up for many more opportunities later in life. Consequences here would be just the opposite. On a smaller scale, sometimes I will stay in and study and do lots of work in one night so that I can go out and drink on the other nights.
As far as actual study tips, this is what I would recommend. Start early if you can, at least get an idea of what you need to do. Lower stress = easier to study. Get a good environment. I pretty much can't get real work done unless I go to the engineering building (open 24/7 at my school) and get a classroom with a few friends. Most of the time we are quiet, but we will trade notes, equation sheets, teach each other things, even get food for each other, and when there are other people studying, you will be more motivated to study. Taking breaks also helps. When you know what needs to get done, this is easier to do, and should be done sparingly, but if you get a solid 45 min or more of good studying done and you start to get distracted, watch a ski edit, check facebook, get a drink, just take 10 to chill. Headphones help a lot, I like over the ear for comfort, and I also really like classical/piano or violin covers. Lastly, drink coffee (but still bring water), and dip can help a lot. I sometimes use pouches (swedish) because you can leave them in longer and you don't have to spit, which can be distracting depending on what you are doing, but I usually get a better buzz from long cut. My friends and I do both pretty regularly during midterms/finals or to finish up a big project. Yeah, its not the healthiest, but a few times won't kill you, and I have no problem starting/stopping whenever I please (guess I'm lucky there). I go through 4-6 pouches in an afternoon to study, or throw in a few healthy pinches, then again at night, for probably 2 weeks straight, and I haven't touched it since.