[Jamie.....]

I never revised for GCSE's but for A levels its different.
For maths I just go over past papers alot, and the teachers make us posters with all the equations etc we need to remember on. If I can't do a question the i'll get help and then look over the topic again.
Then for geography, biology and chemistry I rewrite notes into a simpler form with all the important information. And do a few past papers.