Revision is not just for the night or even a week before a test, it should be part of your weekly routine. Here are some ideas of things you can do:
Grab your booklet and go back a few lessons, cover up the answer to a question and see if you can still answer it clearly and correctly.
Get a blank sheet of paper. Look at the specification (in the course information section) and pick a topic. Write down everything you can remember about that topic (preferably in the form of a mind map). Check against your booklet or a textbook to see if you have forgotten anything.
Flash cards. Write a question on one side (eg "define a priori"; "what was Descartes' first wave of doubt?"; ) and the answer on the other back. Get someone to test you - or make use of the Leitner method (click here for information).