Here’s some advice from a physicist who has spent years on the committee that makes up GRE questions. It’s mostly very good, which is in no way related to the fact that it mostly coincides with advice I’ve tried to give students over the years. He believes more than I do in the validity of the GRE as a test of something useful, but that’s OK.
HT (for this, and for lots of other things I link to): Sean Carroll.
Sometimes I feel like standardized testing is a lot like pharmeceuticals–a need for them simply materializes every time they come up with a new one through clever advertising and social insecurities.
I feel like physics grad schools would get along fine if the PGRE didn’t exist.