I also had one of the display folders mentioned above

It was organised like so: first pocket with cover sheet stating the unit, next pocket page stating the AOS, next pocket full of all the handouts for that AOS, then next pocket contained revision notes for the sac/exam for that AOS. It then continued like this for each AOS, making it easy to locate certain sheets when revision time rolled around.
At the back of my book I then had a pocket for all completed and marked exams, and a pocket full of to-do exams.
I also then of course had a basic notes book for board notes/q's, which was colour coordinated to the display folder. It also had little tabs for where unit 3 and 4 started, as well as each AOS.
Being anal and remaining organised throughout the year really saves on time, which is so essential in year 12