Practice exam papers, honestly it's the best way to learn answers. Make sure you're not just studying loads but studying effectively. Find what type of learner you are, do you learn best by rewriting/talking/watching videos/doing diagrams/chanting. Everyone has a different way but the general thing is you remember 90% of something you read, write, hear and say. So what I do is; I read the book, then make my own notes and I then learn these notes by a combination of rewriting them and then saying them several times without looking at my notes (you're hearing when doing this aswell) then I test myself. And a couple of days later I go back over the notes again so the more you go over it the better you'll remember it.