There are many ways to revise and it depends on the type of learner you are. Personally, for my A-level English exams, I used revision cards with multiple quotes from the various books I studied and kept reading them over and over. These quotes were carefully selected, having looked at past paper questions and figuring out the key themes associated with the book. For example, I studied Mary Shelley's 'Frankenstein' so most topics were concerned with the Gothic genre; a key element, of which, included the notion of the doppelganger. I also found mindmaps very useful and placed these around my bedroom, continously reading them over and using my notes from my excercise book to elaborate. Class discussions were always helpful as other people's ideas would influence my own and this is the key to getting a top grade: individual thoughts that can be backed up effectively with evidence! I hope this helps and good luck with your studies :)