Usually I read through my notes and any revision books first. Then, I make my notes concise and ensure I know the main points off by heart. After that I tend to use Quizlet, make lists, flashcards and mindmaps of the topics, including more detailed points (can listen to music while doing this). If it's a very detailed subject, like Classics, usually I make revision guides. Main thing, however, is to spread out your revision. Do a little everyday.
edit: past papers and reading through mark schemes are really good to do, as well.