I have this one particular bio prof. who is fond of essay questions where you have to write every single detail on a subject and she'll take off 1/2 points for every tiny thing you miss, but she also ties together lots of different topics, so it's important both to memorize EVERYTHING and to understand the big picture. Starting 2-3 weeks before an exam, I read every chapter in its entirety, taking notes on everything, even the details she did not mention in class. I then take those notes and the powerpoints, handouts, and notes from class and combine them, by topic, onto 4x6 notecards with the most important points in an easy-to-memorize bullet format on the front, and relevant drawings on the back. I then read the notecards over and over again, and finally, the day before and morning of the test, I cover the notecards and make sure I really have them memorized.
Speaking of which, I have an exam tomorrow, and I need to go back to studying. 🙄