@
sointoyourself
I'll
try giving you advice for specific subjects.
Bio + Chem: Takes notes on the syllabus dot points. I didn't do either of those subjects for the HSC, but I know people who did. You could try attempting past HSC questions (just stick to multiple choice if you cbf doing the short answers).
English: I've been told that memorising essays is a good way to go about this subject. I didn't try it myself (not for internals), but a LOT of people in my year did, and we seem to have done all right in English this year (118 Band 6s). So try memorising an essay and adapting it to different questions each week.
General Maths: I'll assume that the method I used for 2/3/4U will work for General. Practice a couple of question from each topic from a textbook (no need to do all of them). once you feel reasonably confident with the topic, try practising on questions from past papers (eg. HSC).
Can't comment on Mod History, don't know anything about it.
Hope this helps.