Jesus christ, I'm not even gonna bother. I'm just going to have a bank of ideas/themes and make up my thesis on the spot according to the question. The question, especially for the modules, at my school tend to be so specific that memorising would be rendered impotent. Different questions requires differing levels of nuance to respond to effectively, so yeah I would just prepare by writing out mountains of practice essays at home. Naturally, doing this will compel you to remember the most important aspects anyway, whilst enabling you to tackle different kinds of questions rather than just heavily committing to the one. I'm only going to memorise my creative (because it's awfully difficult to come up with one on the spot whilst other people are bringing in theirs of 1 years' worth of refinement), but I feel like this isn't necessary for the essays. You can 100% get a good mark without trying to memorise anything verbatim. If you know your texts well enough and are prepared to tackle a multiplicity of questions, you should be able to quote from any part of the text accordingly.