This'll sound kinda dumb, but write your own questions. I believe that writing your own questions (based off whatever topics you've studied), correcting them yourself and then getting the teacher to check them is more effective than using someone else's question. This is because you're getting into the head of the examiner and starting to figure out what constitutes a good answer.
You should know what topics will be on the SAC, and the format for questions in Legal are very predictable (ie, discuss, identify, explain, identify and explain, evaluate etc), and you can also guess (roughly) the mark allocations for each kind of question. If you're not too sure, your textbook should also have some practice questions that you can look at, at the end of each chapter. Mine did, anyways, and although I didn't use them much, some of my friends did and they found it quite useful.