Know EVERYTHING back to front.
Know how to answer all types of questions (discuss, explain, deduce, assess, etc), working on structure, and being able to communicate clearly and concisely.
Do past papers (that have solutions) under test conditions and mark them strictly.
Was there anything you missed?
Could you have done something better?
Perhaps make a new document to add all these things that you've missed so you won't make the same mistakes again and add them to your study notes.
By doing all this, you should be set for an awesome mark.