I got A*AA
Revised for around 2-3 months id say with breaks.
First i did a solid month of content, pure content. Made sure i knew everything!! Knew the textbook by heart. Did around 2 hours a day just reading a chapter a day and rewriting it and making sure i understood it.
Then once i finished i would do a recap to make sure i havent forget anything important.
For the next month i did questions, since i did chemistry i did old spec past papers/Chemrevise questions. Biology i downloaded a pack online with like 100+ questions in it (i didnt get time to do it since i had to take a week off revising for something but i know if i did it, it would have helped a lot, as i did it for chem and thats what i got the A* in)
For the final month, it was straight past papers. Id would set a goal, eg for chem4 my goal was 90/100. Id make sure id get 90/100 in each past paper and make sure im improving by at least 2 marks with each past paper.
Its not good enough to just do the past paper, which i see most people doing now a days, you have to go through them properly, analysis the answers in the mark scheme and your answers.
One tip also when doing Past papers is try get someone like a teacher to mark it or if you do mark it yourself make sure your falsely giving yourself extra marks which is easy to do.
Also regrading notes, you can make them if they help you but i didnt see much of a point, all the information in the revision guides/textbook is useful so i used them as my notes c:
Hope this helped.