How to get a good ATAR?

-I do advance and extension english, general maths, business studies, visual art, studies of religion and hospitality. I do not sit my HSC exams until next year but I honestly don't want to be stuck in this hole of a town so any helpful hints for studying or studying plans would be very much appreciated.

I am an average student but I am willing to put in so much effort to achieve an ATAR of 80 so please help me!