Start writing practice essays. Now.
Costargh uploaded that Language Analysis pack. If you need help with structure, by all accounts the pack is brilliant and should be a good tool for you.
I wouldn't recommend actually memorising essays either - perhaps getting a "template" for introductions and/or conclusions would work. I've always been iffy about using other people's phrases - I find something you write on your own is generally sufficient provided you're confident, but if you have to, do it. What I would recommend is after writing your own phrases, read over them, see if they're good or not and compare them with others'; this way, you're not sacrificing the individuality or originality of your writing.
But seriously, the best way to revise is to write lots and lots of essays. Not only does it get you some good practice, it improves your writing speed, makes you better at writing in such conditions and is ultimately the best way to actually put into place any phrases or whatever you may be using. It won't go to waste either, since the end of year exam will have Language Analysis. It is perhaps the most painful, but it is the most useful, and probably the most time-efficient (I really can't imagine just memorising would do much good...).