I don't take the same board as you, so Im not exactly sure about the structure of your paper.
For me, well I do AS Sociology and we have to wrote four essays on the exam. Both Unit 1 and unit 2.
The way I revised was by making about 4 essays on each topic that is most likely to come, I'd learn and understand them, and make sure I've kept an open mind about it, because they may not ask those same questions. However, usually, the content of the essay would apply to any essay regarding that topic (at least that's what I find)
So yeah- write out essays, get them marked by your teacher, learn them, and write 'em in your exam.
Good Luck!