From my experience, know your spins, stalls, emergencies and also keep ahead of the aircraft on your NAV test. Everything else should be fine.
I had to do two test. 1st was the GF test (emergencies, stalls etc.). The 2nd was the NAV. Keep ahead of the aircraft and all will be well. If you are heading off course, point this out to the instructor and correct. No use pointing out and doing nothing about it!
Good Luck!