Everybody is going to tell you to relax.
It won't work, but we'll all tell you that.
For my checkride, I showed up early enough to check out the plane, logbooks, etc. I did manage to find a missing AD endorsement in the plane's logs. In doing so, I managed to walk into the back of a C-152's aileron - and got myself a "Cessna star" on the top of my head (yes, 1 hour before my checkride).
After that, it took my instructor and a few others at the club distracting me to keep me from curling up in the fetal position on the floor.
The examiner was a bit wacky (especially in the oral), but the ride itself was pretty straightforward and easy (again, especially the oral). If you can do your maneuvers well enough to get your instructor and "mock checkride" instructor to say you're ready - you're better than you have to be for the checkride itself.
So, relax if you can, or curse us out for the advice if you must. Just hang in there!