I went up from:
2 grades in Single Science (D to a B), RE (C to an A), Stats (C to an A), English Literature (C to an A)
1 grade in English Language (B to an A) and Maths (B to an A)
Stayed the same in:
French, German, History and Latin (AAAB)
Went down a grade in:
Art (A to a B)
for my mocks: no revision whatsoever
real things: about 0 - 1 hour the day before the exam
so I went from 4As, 3Bs, 3Cs and a D to 8As 3Bs in the real thing
only revised for Latin which I revised about 2 weeks manically every day, was so happy to get a B! I was awful!