Cheat sheets are an absolute advantage. While studying for my Series 7, our firm enrolled all of us in a week long prep class and while the class was great I only really took away two things: the very gritty details about options and how to use a cheat sheet effectively. The easiest way to maximize this tool is to break a piece of paper into 8 quadrants and fill each with a series of equations (i.e. all volumes and surface area equations in one).

Once you are comfortable that you have all of the information you want, practice drawing it at least twice a day without looking at it. At first you’ll probably do terribly, but after a few days you will figure out how to do it quicker and quicker; my baseline for practice was four minutes, but by the end I had it down to three.

A few other tools I used were BenchPrep’s GMAT course, which I bought on Groupon for $15, and a question add-on from mba.com for $40. Along with the ~$5 colored note cards I bought (there is some fascinating science behind studying with colored paper/pens/highlighters) I spent less than $60 on my GMAT studying.