Mathematics - Key to doing well is completing past papers. Go to
https://thsconline.github.io/s/yr12/Maths/, find some trial papers (you have A BUNCH to choose from) and continuously do them. Make sure you mark your answers and I suggest keeping a word document with common mistakes that you make. Do a few past papers a day (preferably 2 - try to do them within 2 hours and not 3) if you can or just pick 7 past papers that you will do that week and make sure you do them. If you don't understand theory, go to a textbook and learn it by completing the worked exercises - know the basics and the past papers will guide you. This is as active as it can get in maths.
English - I didn't do standard, but study techniques associated with advanced should be identical. Firstly you need to REALLY understand the modules (I will not explain this as Boredofstudies has a billion guides on modules). Then you must understand your texts well and fully comprehend essay writing (clear thesis/idea and continuous reinforcement of that idea or otherwise). You have two options from this point; you can either memorise a bunch of quotes and techniques and categorise them based on themes/overarching paragraph ideas, or you can memorise a few adaptable essays. I memorised a bunch of paragraphs (and knew how to place them in an essay) for my trial exams and the HSC. For studying; you need to memorise the aforementioned quotes/essays throughout the year or when you get the chance. If you have 2 or 3 hours spare, write essays. Do this as you go through each module and by the end of the year, you'll have semi-memorised a bunch of essays/quotes (remember to remain consistent and revise so you don't completely forget everything). Again, this is the most active way in english -- just make sure you get feedback on your essays - ask teachers, peers or use forums. (Personally, it was not until a few months before my trial exams that I started picking up these study techniques, so it's good that you are).
Business studies - Consistently revise the syllabus - memorise it completely. As you go through each topic; ensure by the end of it that you know the syllabus and can define every term in the syllabus. What I did was I went through the syllabus and asked myself if I could write a hypothetical essay/business report paragraph on that dotpoint. If I could, I was fine with it and If I could not, I would revise. From here, you need to complete a bunch of past papers (which can also be found on thsconline). Make sure you get these marked (either by you, a peer or your teacher).
Most active way of studying = consistent practice through past papers (writing essays, getting them marked and
understanding where you went wrong).
This post is probably as generic as it can get, but this is what I did.