I'm doing English lit to for tomorrow too and what I've done to prepare is just go through several more difficult poems (for me) and I've done analyses of them based on the question. I think that the point of the questions being vague is so you can get away with writing about what ever you want, it'll also help if you show your skills through your writing. I don't know much about English lit tomorrow but I've heard from a few people that, supposedly, the lit exam will have some a level stuff....but you should probably take that with a pinch of salt.
The poems I've analysed have been from Shakespeare, John Donne and some other more traditional poets, but don't forget to study some more contemporary work too. If anything, go back to basics in the lit exam and focus on a minimum of 3 key points and just analyse the hell out the them, like the use of the metaphor and crap, you get my point, right?
I've looked at the History paper and again you've been given a lot of freedom to write about what you know, so what I'd say is pretend that you're in your usual GCSE class writing an essay on anything you know (depending on the history topics you've done, mine are Protest, Germany and Medicine), like Galen's influence on history or something and then treat it like a complete 16 mark essay on it and that way you'll be able to give yourself some sort of structure to write about e.g. intro, 3 mains points conclusion.
I hope this helps and good luck!