I didnt even look at one of the topics for my Geography exam until the morning of the HSC exam, and I still managed to get a band 6 in it. It's all about training myself to memorise things....I've done it ever since year 7. You'll need another person to help you with it for it to work best, but it is possible to do it alone.
What you need to do is write down whatever it is you are trying to learn, then condense this as much as you can. Then from each sentence, pick out a key word (or key words if neccesary). write these words on a separate peice of paper. Put away the peice of paper which has all of the information on itor give it to the person helping you, and use the papaer with the key words on it to jog your memory. Try to explain as much information as you can about each of the key words, and if you have someone helping you, get them to put a small mark near stuff you have forgotten. Then you can see which information you need to concentrate on most. S
ometimes it helped me if I put little symbols near my keywords...this helped especially for art, but it worked for other subjects too....if there is something you have trouble learning, doodle something which makes you think of that thing near it so that when you study your notes, you associate that doodle with the information you need to learn. Sometimes when I was writing essays, I'd suddenly remember something to put in later on in the essay, and rather than jotting down a stream of words and losing my present train of thought, I'd just scribble the little doodle I'd used when studying on the exam paper near the question I was referring to. You might end up with lots of little pictures all over the place, but it really really helps. To this day, if I see my doodles in my old notes or on old exam papers I have, I can recall whatever information I used that doodle to remember.