2 Answers

If you are looking for an easy answer that doesn't require much from you, good luck in finding that.  
Find out what material is going to be covered in the final exams and if there will be essay questions.  
Review your notes (if you have them), study guides, and any quizzes and/or tests you have had returned.  If you have time, read again the material from the texts. If not, go to the ends of the sections and chapters....aren't there some review questions???
As far as essay questions, pay attention here (I once got a B in a class where I'd A'd everything else because my essay answers weren't complete enough.)  LISTEN UP:
1.  Who, What, When, Where, Why, How    are generally the way questions begin.  Your answer needs to address the questions.  
2.  When you are done writing (and try to spell and use correct grammar), read your answer. It should leave you with no doubt "who", "what", "when", "where", "why", and/or "how".  In fact, you should actually KNOW what the question is without referring back to it because your answer is so complete.

Cookie Monster (who) drove his race car at speeds of 268 mph (what) on December 23, 2010 (when) at the Cinnamon Bun Raceway in Biola, California (where) and won the Cinnamon Bun Out In The Sticks Race (why), beating his nearest competitor, Oscar the Grouch, by more than 63 miles (how). 

Some questions won't require all those "?" be answered, but it is your responsibility to ask yourself each one as you proofread and decide whether or not the info is relevant and needed.  

One last thing.  Start now.  Set aside a specific amount of time for each subject on a daily basis and don't deviate from your schedule.  This requires discipline.  Don't ask me about that.  :(