But with the book handy, you can get the answer easily. It's nice to be ready for as many gimmes as possible. This is not the time to be frugal. Buy CERM7 because, although it's not perfect, it's much better than any other book out there. The index is great.
Color coding the labels by section is a good idea.
Speed is essential when you have only 6 minutes per problem. SLOW DOWN and read each question through to the end. Sure, you have only have 6 minutes for each question, but all the more reason not to waste time jumping to conclusions about what's being asked. Often they'll give you data at the end of the questions that you might otherwise start to calculate if you don't read to the end first. I found myself not reading the whole problem, and I wasted time doing calculations or looking things up only to discover that the question was asking for something different than my initial assumption.