Review all of your notes every day , five days a week. This should take just a few minutes and the more times you look at them the quicker the review will go. This constant re-enforcement is much more effective than cramming many hours just before an exam. Prepare an outline for the class in order to do serious study. Play on weekends .
Balance is an important part of good overall and effective study habits.
Learn to have fun in class and in your studies. Don't worry about what your peers will think. You have the rest of your life to live, and how you live that life will in part be based on how well you do in your studies.