Honestly, UMAT is quite a limiting exam to study for though. You'll approach your limit of how much you can improve quite early so make sure you're keeping track of your progress and don't spend excessive amounts of time on it and sacrifice your ENTER at its expense. I started my study about a week after mid-year exams so that gave me around 5 or 6 weeks and that in itself was enough for me to hit my limit. Although I wouldn't recommend this method and it's better to space out your study a bit more, just remember that the UMAT isn't an entirely 'studyable' test and that you just have to admit to the fact that you can't progress any more. It's hard I know, but seriously, I've seen people who've studied for the UMAT from year 11 to the UMAT exam in year 12 and still obtained UMAT marks which couldn't get him into Medicine, together with a slight sacrifice in ENTER due to the time wasted.