Hi Aaron - last minute advice indeed! This is going to sound very basic but just make sure you can practice what you've been taught and try to stay relaxed; my skills test was about the most relaxed flight I'd had up to that point, but then again to say I was tense at the start of the course would be a massive understatement. It did help to know that the aircraft was capable of a lot more than I needed from it also - 45 degree turns are nothing to worry about when you've experienced 90 degrees (which I expect is nothing once you start going upside down
).
You will know if you are ready - obviously you've done your solo QXC and the 10 hours required so you can handle the aircraft, just a matter of making sure you know the drills, particularly PFL/EFATO. The worst bit for me was the various types of landings at the end, but after you pass remember that you can then just fly to where you're going and land once, no more circuits
Going through drills sat at home works well, and make sure you have any paperwork you need where you can get to it (in your kneeboard).
Believe in yourself and good luck!