Revise in order?Watch
You could watch video's, go through your school notes/booklet or go through the revision booklet your exam board has.
But you need to put your revision into practice by doing past papers. That is the best way to get a higher grade. Then if you find any questions hard, check your school booklet/notes. Then check the mark scheme and you will understand how the exam board wants you to answer questions so you won't miss out any marks.
Ah ok thanks- what about maths related questions and stats? should I do them after revising everything, with the topic at the time or before revising everything?
In A level, I find stats the hardest. But what I do to revise it, is going through my book I use in school, complete the questions I did in class, then homework again. Then I go onto past papers.
It may sound simple, but the repetition of questions is the best way to revise for maths.