Set aside 15 minutes each week to review each subject. Review class notes, homework, reading assignments to get the overview and keep track of the direction the course is taking. To avoid completely re-reading textbook assignments, prepare them for reviewing by underlining key words and phrases and outlining the underlined material. Do not be afraid to ask questions about material you do not understand. You cannot remember something unless you first understand it.
Professors like to find students who really want to understand.
In reviewing, spend the most time on material that is least familiar, and review briefly the material that is most familiar. In reviewing, prepare a list of likely test questions and make certain that you can give the correct answers in your own words. If you have trouble with essay tests, spend some of your study time actually writing complete answers to questions. Students often have a great gap between thinking an answer and actually putting it on a page in writing. Keep, correct, and review returned quizzes and exams.