Unlike a lot of other people here, I still have continued to express my social life that I well and truly am proud to have during Year 12. I look forward to balancing Friday's and Saturdays with my mates, parties, girls, and everything else. Hell I wouldn't mind a bit of the PSP and Ps2 during that time as well. Maybe watch new ep's of Lost, O.C or Prison Break with my mates as well.
I go hard out and focus on Monday to Thursday, and on Sunday I do a bit of a laid back brush up on work. I am a bit ahead in reading and some work, and eager to do work all the time.
I know a lot of you guys don't have lives (e.g kadlil I can see you are really putting in effort and sucking out your time already, even from preliminary) but to those with other areas of their life, make sure to balance what you have. If you don't have much of a social life on weekends, don't waste your time trying to create a new aspect of it, that's one advice I got from my friend who is in uni now.
Good luck sticking to Year 12 and habits. We all need it.