El Garbo's three step guide to HSC glory:
1. Know the syllabus. If you know it, you know exactly what you need to learn, and you won't do any more studying than you have to. Why waste time during stuvac when you can be relaxing and chilling out?
2. Relax and just chill. Some people spend upwards of ten hours a day on study. I think a healthy mixture of studying and relaxing is the ticket. A healthy ratio is 2 hours of relaxing per one hour of study, at most. It keeps you relaxed, stress free, and gives you that competitive edge over all your panicked rivals.
3. Share information. Up until now you've been jostling with everyone in your grade for rank, and the competition has been cut-throat. However, from here on in, your grade's marks will collectively scale each other up or down, depending on how well everyone does. So if you've made up some kick ass study notes, give them to everyone in your class, and make sure they share all their stuff too. With everyone getting better marks, you'll drag everyone's UAI up that little bit higher.
Other than that, there's nothing you can do. There's a few tricks you can employ while you study though, I personally recommend pulling up one of those poolside recliners, finding a nice sunny spot in the backyard, stripping down to your swimmers and working on a tan while you study. Also, have a great deal of cold drinks at hand and some relaxing music. I recommend 'Buena Vista Social Club'. If you absolutely have to study, do it in style. You'll come out the back of it not only smarter, but lookin' fine for the three month break that awaits...