Make sure you do all the homework set for every subject even if you think it's not necessary.
For maths, make sure you start creating your bound reference during the year. Chances are, you won't use it during your exam at all, but the act of writing out what you've learnt that day into a book helps to consolidate it. Also, it acts as a good reference if you forget something when you go to study later.
Try and give yourself the weekends free. This won't be possible as exams/SACs approach, but at other times, it can be a good incentive to get your work done early if you have a fun weekend to look forward to.
If you get a part time job in the year, make sure you're not taking more than 1 shift a week. This can be challenging (one of the harder things I found about VCE) but it is definitely worth it.
For English, continual essay writing is key for achieving high scores. Just keep writing out essays and giving them to your teacher/other teachers to mark. You'll quickly find the quality of your writing improves. However, don't just write some shitty, sloppy piece to ease your conscience. You'd be better off writing nothing than that.
Chemistry... Just keep up with the workload. Seriously, don't fall behind and attempt the extra questions your teacher doesn't set for homework.