^^ Bloody oath, this is a great method. I used to have one fat binder as well, but it actually got totally full and so in my last few terms I switched to a smaller "working" binder with bare essentials and kept most of my stuff at home. Do this if you're getting a binder, it'll save you a lot of pain.I didn't do this but I would if I did Y12 again
Have a binder with plastic dividers for you subjects, you bring this and paper with you to school. I would also print all syllabuses now and bring them in this binder so that you can always look at the syllabus when in class or want to study during frees/recess/lunch. If u do math I would recommend you print the HSC formula sheet too and literally always have it next to you when you're doing math, there is no point in not using the formula sheet.
Have a big binder for each subject at home into which you put work that you don't need in your school binder in the upcoming days. This binder can have dividers/sticky notes for particular topics. I would also print syllabuses for these binders so you don't have to swap them around all the time.
This way you don't have a fat binder at school (like I did) and all your work is organised and easy to find.