The examiner for my test was the same person who I flew with on the nav test and was one of the senior instructors at my flying club. I'd flown with him a few times before, so I guess he had an idea of my capabilities.
I found out after everything was signed off that he used the nav test to mentally tick the boxes for the flight test. This explained why I got an EFATO straight after departure and then this ex-RAF chap wanted to go off and do some rather odd stuff such as some spins (this is in the mid-90's after it had been removed from the syllabus). He also directed me to fly into some clouds, covered the AI and DI and said 'whatcha gonna do now?', which prompted me to do a 180 with turn coordinator and compass.
Make sure you do a thorough preflight, since I found that the air filter thingy (technical term) below the landing light on the 152 was installed upside down. The examiner was very pleased with me, but incredibly angry with the other instructors who had not noticed during the previous 20 hours of flying.
Just relax, make sure you talk through the proceedures as you go through them. It might seem a bit silly at first if you are not used to it, but it lets the examiner know that you know. Don't do what I did and reel off the entire engine restart checklist after the the examiner reduces power to idle and says "right, you heard a bang and there's a piston popping out of the top of the cowling". I think that if you basically get around without endangering yourself, the examiner or others you'll be fine.
Best of luck,
Gareth.