Make sure to do your coursework properly! I have friends that got A*s in their exams but because their coursework was a low A, a B or a C their grade was dropped. You really don't want to have that!
Also, make sure that you learn everything properly. I found that some of the smaller stuff that people usually ignore can get you an easy mark or two in the paper that you would only get if you revise everything thoroughly. That doesn't seem like a huge difference but when you miss that A* by a single mark you will regret not learning the smaller things.