I'd be lying through my teeth if I told you that I've been studying for Advanced every night for the past twelve months. Ideally, the senior independent study (a la regurgitated advice from the typical school diary) time at home is 2.5 hours or more, so I'd say if you're committed to doing nightly, strict study, do at least half an hour; go over notes from class, re-read handouts and texts, highlight important points, etc. etc.
I found that getting extra notes off my teacher and constantly doing practice questions and essays really helped refine my exam technique for Advanced (generally this works for all the English courses, but particularly Adv.), and so on. Feedback from my teacher is one of the main thing I thrived on; I'd constantly ask her to read over my responses (and the re-written responses, and the re-written re-written ones ...) and give them appropriate marks, suggest where I'd gone wrong, etc. This comes in invaluable handy around exam time.
But in the big chunks of academic lull in between, unless you're doing texts that all genuinely interest you, forcing yourself to make notes is a healthy but painful strategy; make them, and then tell them to fuck off if you detest English to the point where you complain to your teacher that the course seems too female-oriented because all the texts you do suck arse (*cough*). Read over them the next day, make more notes, and so forth. It's a ... nice ... cycle of motivation. Really, it is.
HSC Advanced will broaden your perspective (I.E., you can never think of things as simply as you could before ... ever again ...), so be prepared to embrace rather digressive concepts that appear to have little to do with the texts when first introduced, but then click and make perfect sense afterwards.
With relatedededed texts, since chances are that you'll be studying a diversity of prescribed/set texts, make it easier on yourself by choosing something in a different medium but has the same impression; for example, if one does Powerplay with
Antony & Cleopatra (NEVER again ... *twitches*), "Gladiator" or "Troy" would make for one of many ideal related texts. Aaaaand so forth. That advice is probably something your English teacher's projectile-vomited at you before, so with that in mind ...
... have fun! ... Well, maybe don't force it, but enjoy what you can, work hard, make notes, simplify your answers and make sure you have all the foundation of details down before you begin go pile on the interpretative stuff.
Best of luck with Advanced!
And now I'm going to head off to bed and do something called "sleep". What an unfamiliar phenomenon ...