How to Revise History and Economics?

I find revising History and Economics quite hard. As well as the A2 exams, I am also retaking an AS exam from both as it dragged my overall grade down. I've already made notes on chapters from the textbook for my A2 history (Russia), during term time. It's quite hard to do essays though, because the essay technique is comparative, and we haven't studied all the liberal leaders yet. For econ, I'm just trying to make new notes but my teacher has shoved a lot of duplicated notes down our throats so it's proving to be a nightmare. I'm practicing essays, but I need my textbook as aid for some questions. Help!