Something i did when i'd become quite confident in 2u was that i printed out all the question 9s and 10s since 2007, and made them into a "monster trial", so basically Q1 was 2007 Q9, Q2 2007 Q10, and so on until Q10 was 2011 Q10
Doing this under time conditions should take 3 hours. But only when you're confident! You could go on to do this with 2002-2006 as well
It's great practice for maximising your marks in Q9 and 10 (now 15 and 16) which should essentially get you 95+ (i made many silly mistakes in my HSC from q12 and 13 so you may want to also practice doing easier questions under timed conditions)
the most important thing, though, is doing as many papers possible, without of course disregarding other subjects, UNDER EXAM CONDITIONS. Even if you finish in 1 and a half hours, just keep going until you've checked your paper over 3-5 times, essentially this is what you'll be doing in hsc/trials and you need to know how you should be checking. Mark yourself harshly with the strictest marking guidelines so that you can ensure to get full marks for each question thus maximising your mark - imitate your maths teacher marking your trial paper on his/her worst day haha
and don't do one question then check the answer then do another and check the answer - this is silly unless it's your first ever past paper. Do a FULL EXAM, again under exam conditions, and then check your answers.
I personally finished about 20-30 trial papers and did HSC papers from 2001-2011 when i sat for 2u, but i was accelerated so i had more time on my hands - finished about 30-40 trials for 3u. So just do as many as you possibly can, perhaps one a day but would be better to do 1 every second day to fit in your other subjects..
