The way i have always revised is by memorizing past paper answers word for word. It's definately the most efficient way to revise because a lot of the marks are got by using the exact wording and phrases that the examiners are looking for. Learn a couple of past papers by heart and you'll make upwards of a B easily. Examiners always have favorite questions that crop up year after year so you're just wasting your time if you try learning the whole syllabus.
This method may do well for you now, but its a very bad habit to be falling into. Rote learning only works for the early stages and leaves you in difficult positions regarding unseen questions.
I know some people who got through school using this, but totally crashed once they hit uni. Not only because uni exams can vary greatly from past papers, but also because it requires a solid understanding of things taught at school (which may or may not be revised in lectures).
Its easy to say "Oh I'll just learn the paper this time and study properly next time", but frankly its a habit that is hard to break and doesn't benefit you at all in the long run.