Create Quote, Technique, Analysis tables, separating them by different parts of the text (e.g for plays, you can separate them by different acts) and colour-coordinate them by the main themes/ideas.
Create base essays that can broadly fit into a lot of different texts, using the table you created. A lot of times, the essays that you write in the HSC are going to be asking roughly the same thing and about the themes so with a bit of practice, creating new topic sentences and introductions under timed conditions, you should be able to use at least 85% of your memorised base essay. If your teachers allow, this is a good time to email/give them your base essay so they can help you make corrections