You know how we prepare? We don't because they usually end up telling us the night before so we can't even get hydrated enough to be ready for it the next day. Our platoon still has the highest scores in the command though.
The only Marines I ever hear discussing getting prepared for a PFT or CFT are non 03xx.
But do you incorporate a fitness routine in your lifestyle? By that I mean, eating decently, and working out correctly.