Not actually a student, but i read quite a few pass and fail stories on here while learning to drive, so I've registered to pay back a little of that help:
First time I'd booked the test several weeks earlier, but when the time came still wasn't expecting to pass. Decided to take it anyway though, as a 'practice test' if you like. Was a bit nervous, but as I was assuming it was a fail anyway, more relaxed than I would have been otherwise. Actually ended up with only one major, on reversing round a corner (my weakest maneuver at the time, and I was WAY over the other side of the road) and a couple of minors. I'd done things I'd assumed would have been majors which didn't show up, and I was surprised and pleased to only fail on one thing. Examiner that time was very friendly and relaxed.
Luckily managed to book a cancelation for a couple of weeks later, but my regular instructor wasn't available. Switched to another guy and did I think 9 hours of extra lessons before taking the test. Found the new car a lot easier to stall, but liked the instructor a bit better. This test was a complete nightmare though. Examiner had a completely different attitude, and while she was fair she just gave the impression of having better things to do, and that she was looking for reasons to fail you, rather than pass you. I also made a daft mistake right at the start which I should have let go, but put me in a foul mood. Here's how it went.
*random beeping noise I've never heard before just after we pull out from a junction*
Me, looking around frantically and assuming it must be the instructor's sat nav running out of battery or something: I've no idea what that sound is, sorry...
Examiner, with an eye roll: I think you'll find your handbrake's still on.
I got myself all annoyed about that, it affected my driving, stalled a few times, and generally felt rubbish. My actual major fault that failed me was at a busy roundabout - I'd missed (or thought I had) a couple of opportunities to go, and then took one I shouldn't have. Dual controls were used, fair cop, I've failed. There was another one close to the test center where she pushed the wheel to move us away from a parked car, but to be honest I'm not sure that was necessary and my instructor, who was watching us come past at that point, said he hadn't seen a problem. But anyway, had failed earlier, so no worries. The mistake with the handbrake early on was only a minor - if I'd been able to let that go and stay calm I might have passed.
Third time, another quick cancellation fortunately (I don't mind failing, it's the risk of an 8 week wait I hated). Examiner from the first test again, was very pleased to see him, lovely bloke. Still felt a bit nervous, but stayed calm enough to avoid any daft mistakes - almost tried to move off in second but caught myself, that kind of thing. Picked up three minors for speed, one for nudging the kerb on reverse park, and one for going through a pedestrian crossing at amber - whoever pressed the button had already left, might have been a major if they'd have been stood there I guess. No other majors, job done, never have to do it again.
General advice I'd give -
1) Get used to driving without feedback. My instructors were constantly giving it 'good.... little bit fast there.... could have been closer to the kerb just then.... excellent....' For at least a few hours prior to the test, tell 'em to shut up and let you drive. I found even after simple junctions and so on, things I can do in my sleep, I was missing that feedback and wondering if I'd done it right or not. That meant I wasn't concentrating on what was coming up.
2) Do at least two mock tests with your examiner, and tell 'em you want them to be tough - hardest test route they can think of, your weakest maneuver (or do all three), giving you directions later than usual, sounding pissed off. Harder the mocks are, easier the test'll seem.
3) You've got to stay calm and focused. Unfriendly examiners, someone cutting you up, making a mistake at a junction - got to be like water off a duck's back. Maybe walk in telling yourself you're going to fail, you're just going to try not to fail too badly.
4) Know your roads back to front. I could draw you maps of our local dual carriageway spiral roundabouts that would rival the AA Road Atlas. Know where the bus lanes, the yellow boxes, are. I used to track driving lessons on my phone and then use that to go and check out places I'd made mistakes on Google Earth.