If what your taking has coursework(s) make sure you get a high mark(s) in it as it keeps the pressure off of you a bit and that way even if you don't get so good exam results you can salvage a good enough pass that you might be pleased with.
As Multiplexed said don't leave anything to late. In theory doing it the night you get it would be best but in reality that probably won't happen but as soon as you can is good aslong as you get it in by the date stated by the teacher.
Use any free's you get for revision or even homework/coursework and not a lounge around as when it's nearer the exam time you will be soiling yourself about it.
Make sure you understand your notes. I took some last year that I didn't understand the next day
and it hindered my revision a bit.
A good thing to get into is a time table for home where certain times are set aside for homework/coursework/revision. Start it early so it's a stress free little and often aproach so your planning ahead and not cramming it all into you right before the exams which probably won't work and will get you stressed. Also the certain times for doing these things will make it so your brain is expecting to revise and the like.
Although you have to do revision don't over do it. Give yourself breaks every half hour for 5-10mins listening to music, meditating or something like that so you can give your brain time to absorb what you have revised. If you don't give your brain a break it's not going to work that well. The first 15mins are said to be the best while revising something.
Also try not to revise more than 2 subjects a day. It doesn't useually help your brain retain valuable information.