How am I going to remember to get all of these different factors into essays in my exam?

Arguably more important than practicing writing full essays is practicing essay plans. If you can get into a good routine of producing concise plans which make sense to you and reflect all of the main points you know you need to address, you will be able to build a well-structured essay and you will be less likely to forget points that may have occurred to you before you had a chance to write it into the essay. Let's work on building an essay plan system that suits you...