The best time to study is right before or after class, and you don't want to wear yourself too thin.
Even if it is stuff you think you already know, know what is expected of you.
For every hour you spend in class, you will probably need to study two hours outside of class. If possible, study for each subject at the same time and in the same place. Go over your notes from class and make sure they are clear. Be sure to do reading assignments, and read ahead whenever possible.
The chosen place should have a desk, a comfortable chair, good lighting, any needed supplies, and should be as free of distraction as possible. This place should be a place for study, not for other things.
What takes an hour to do during the day may take an hour and a half at night.
Take a ten-minute break after every hour of study. Avoid scheduling long blocks of time for studying. Try to arrange several short study sessions throughout the day.
Find out lab times and locations and use them; other resources can include tutors, videos, computer programs, and alternative texts. Get to know your professors and advisors. Ask questions.
Studies show that students who study with someone routinely receive better grades. Teaching a concept or new idea to someone else is a sure way for you to understand it. Studying in a group or with a partner can sometimes become too social. It is important to stay focused.
Work on your hardest subjects at a time when you are fresh. Putting them off until you're tired compounds the problem.
Studying on four hours of sleep and an empty stomach or junk food diet is a waste of time. Avoid caffeine just before or just after studying.