Hi, I'm curently studying A2 Geography and found that reading my notes through didn't really do much for me at AS.
I found drawing diagrams, recording myself explaining things (I know that sounds crazy!). I even explained things to my parents and friends, how things were formed and why/whats involved! This helped me a lot.
Also, practice exam questions in exam times, this will help you prepare for what the questions are like and how long you have to answer them. Thats what I'm doing now! My A2 examm is in a few weeks, and I'm cramming in so much revision lol.
Hope some of this helps. Good luck, keep calm and try and get some sleep... dont do all nighters (y) x