I'll start off with this, coming from an EE background we always had to learn material and then "apply it" to other situations. I had a friend who was a Bio major that I'd help a little on the PS section. All he cared about was memorizing everything and not really how to apply it correctly. Maybe that's the Bio mentality to memorize everything. (I know not all Bio majors are like this. I'm just trying to prove a point). What I did was go over ALL the material multiple times before ever approaching problems. I did not take a review class and studied on my own. However, all my friends did so I used ExamKrackers, Princeton, Kaplan, and Berkeley material. I think Princeton has the best material. I've had to have gone through every section thoroughly 10 times. Whatever specific topic I was weak on I'd use the other books to strengthen then. Read to understand!!! Whenever I encountered a problem, since I was very familiar with the material in the PS, I'd know what area the problem covered. I'll remember all the equations that applied to those problems. I think that if you understand what all the variables in an equation mean then it makes it a lot easier to apply to another problem. Hope that helps somewhat.
