Hand write your own study notes using textbooks, online sources and other peoples notes (I did this for sciences&maths and felt that both the act of writing your own notes and doing it by hand had tangible benefits)
Do a shit tonne of exercises for mx1 and mx2. Like, do a lot, then do some more. This older girl who did well told me to do 50 Cambridge-length questions (i.e. the equivalent in length and difficulty of 2-3 Cambridge exercises, taken from a variety of textbooks) per sub-topic. I reckon I did more (it helped that my maths teacher refused to acknowledge the existence of other subjects and gave us an impossible workload) and every last question was worth it.
If you're not naturally talented at English, rote learning essays works fine. Hell, I know some English talents who memorise essays anyway. Just make sure you know how to adapt your essays to the question. Also, ideally you'd want to make sure your pre-prepared responses are top band material, and a good way to do that is by writing your first draft as soon as possible and getting lots of feedback from your teacher or tutor. Write revisions, submit them for more feedback, don't stop until you're gold.
Surround yourself with highly motivated people. It's one of the best ways to keep yourself motivated, even if you have a strong desire to fulfill your personal goals. Conversely, encourage people around you who don't work hard. If that doesn't work, make sure you don't get tempted into slacking off like them. Seriously, I've seen friends tempted into laziness by other friends. A couple guys would rather game instead of study, some other guy thinks it must be okay and doesn't study either, none of them end up fulfilling their potential, it's a sad thing.
Form a study group. You don't need to actually meet up outside of school, you just need 2-3 hard working people to sit next to in class, keep in constant contact via Fb or Skype messenger to ask questions & share notes, and generally attach yourself to. It helps if they're a bit smarter than you so that they can pull you up (but not too much smarter since obviously you don't want to be a complete burden on them -- although god knows I was
). I guess this strategy is only viable at a decently ranked school -- less viable if you're at a low ranking school & trying to leave the rest of your cohort in the dust to improve your internals.
You can listen to music while grinding maths/science exercises but as soon as you feel your train of thought is starting to go in circles, take off the headphones and do your study in silence. It can get boring, but it's worth it.
Take constant breaks, like every hour or so, unless you're doing a past paper in which case you should do the whole paper at once. Also, if you need to clear your head, try tea. I must have been drinking 3-4 cups a night at my peak. Great for studying late at night.
Leave enough time to have a hobby/go jogging/hang out with your friends every so often. However, study and sleep are your priorities. Go home, eat, study, play around if you have the time, and be in bed by midnight. If you want a romantic relationship, consider long distance. I worked like 4 hours a week night (mostly maths) on weekdays and maybe 5-6 on weekends. Prior to trials, my study hours jumped to like 6+ on week nights (2 past papers) and every waking hour on weekends. After trials, I was able to pace myself a bit more, because there was so much more time and no classes. Do less, do more, it entirely depends on your personal needs. If you're struggling with a topic or even a subject in general, throwing more study hours at it is an acceptable remedy.
Also, keep in mind a realistic picture of where you are, versus where you want to be. At the start of each term, I blutacked a sheet of paper onto my wall. It summarised my marks in each exam, my ranks, my ATAR estimates, and a personal evaluation of my performance in each subject from the previous term i.e. "great", "good", "meh" or "shit". Constantly keeping both your failures and successes in mind is very useful, I think. Learning from your mistakes and all that. I screwed up some exams in my HSC year, but I never screwed up on the same subject twice. By the time the final HSC exams come around, you want to have finished screwing up and be ready to kill all of your exams.
