Get more sleep: if you're a procrastinator, it's likely that you're up pretty late trying to study the night before an exam. I can function without a lot of sleep, but the more rested you are, the better you'll do on exams.
Do what works for you: some people learn best from making flash cards (like me!) and some people learn and retain more from writing things over and over. Whatever your shtick is, do that. Wasting time on trying to study from something that you know isn't going to help will just make you more stressed.
Memorization strategies: sometimes certain topics just don't stick in your brain. If this is the case, trying to create a way to memorize the topic can help. Create acronyms for words you do know so that on the day of the exam, you can write the acronym down on the test paper and remember it.
Sign up for Luvo Learn: I wish more than anything that I had this study tool years ago rather than just finding it in my senior year of college. No matter what subject you're trying to cram to remember, Luvo Learn has it!