This method worked for me, not sure if it will work for you.
I done this in the last month towards the HSC, basically for 2U, I looked at quite alot of past papers from other schools (Ruse, Baulko, etc.) and I would "attempt" to do the questions which I have trouble with. If I knew how to do them (which most of the time was not the case), then great, if I didn't know how to do them, then also great. Because I ended up looking at the answers, and trying to understand the process. It probably took me about 5 papers to go through until I started to understand. Even though for some this might seem non-efficient because I'm just looking at the answers, but once I started noticing a trend in the process leading up to the answer, I had an idea of how to approach the question.