I found my skills test pretty hard. I did both the nav and handling bits in one go (you can opt to do them separately, but I guess this depends on the examiner as well), so you end up flying for over 2 hours, which was by far the longest flight I'd done. Add to that the general stress of being 'examined' (although my examiner was great and did his best to relax me) and it was very draining.
We did the nav first, and then the handling. My PFL was a nightmare, mainly I think due to fatigue and nerves, and I ended up with a partial pass. This meant I had to do a second test to re-do the PFL. For this we just flew to the local area, did a PFL, and flew back. Although the PFL is the point of this exercise, the examiner is also checking the other parts of the flight as well, so if, for example, your R/T was fine the first time, but rubbish the second, you could end up failing completely.
My advice would be to do a pretend test with your instructor beforehand. I did do this, but not both the sections in one go, and I did find the length a problem. Make sure you're rested, brush up on the POH for your plane as there is an oral test about it, and try and relax.
The examiner wants you to pass, he's not trying to trick you, so I'm sure all will be fine.