So I may or may not be a little late in contributing to this thread, however, hopefully this will be of some help! I'm sitting the HSC this year too, so don't worry, we're in this together, I GOT YOU. English and similar subjects (Visual Arts, Drama) have always been my strong point, but like anyone, ya still have to study for it!
Basically, what I did (and what I'm doing currently) is that I'm pre-writing all of my essays / creative texts as anyone would. But here's the thing that really saved me in my half yearly. Don't memorise your essay word for word, memorise your key points, your general thesis, your quotes and your overall flow of the essay (unless you already know the essay question of course!). The reason I say this is because you want to be able to mould your essay into whatever it is your markers chuck at you- what happens if your essay doesn't suit the question at all? You either brainfart, wing it or you reiterate the essay you've memorised. You may have an amazing essay but at the end of the day, if it doesn't fit the question, MANY MARKS WILL BE LOST. Again, memorise bits and pieces but don't cram it all into your head. Same goes with creative, it's all about adaptability and being able to mould your responses! What I normally do after this point is take a look at some essay questions from the previous years and depending on how I feel, I either try to rewrite my essay and shape it to fit the question or I write in dot points how I would approach the question using the essay that was pre-prepared.
With short answers... the only thing you can really do is practice, so past papers all the way! Because I'm lazy, I normally just dot point on a separate page some techniques, a quick analysis and what I would say to answer the question, then ofc, just check if you're on the right track
Hope this helps and good luck!