Remember, the examiner wants you to pass!!
It is far easier on paperwork and emotions to pass a student. He really will be silently willing you on.
I am sure that I can speak for most examiners that they want you to come back afterwards and say they mildly engoyed it.
HE/SHE IS ON YOUR SIDE! Normally an examiner can feel whether he will pass you or not from the first few moments in the aircraft together. Above all it's your attitude to flying in my mind coupled with a reasonable amount of skill that is a winner.
Just impress the examiner in those first few minutes with a good sound display of airmanship and just relax and try not to make any BIG errors. If you do, then pile on as much airmanship as you can, forget it, and hope for the best.