Quality over QuantityI would say focus on
good quality revision that's consistent rather than trying to blast 4hrs straight over 1 or 2 out of 7 days. I did that at GCSE. Unless you have an eidetic memory, it won't work.
You will remember things far better if you
read over the areas you revised yesterday or the day before for e.g 15 mins. Do short but consistent periods.
I did 25 minute revision sessions each time using what's known as the
'Pomodoro technique'. You do 25 minutes revision, 5 minute break then another 25 minutes and then read over what you have revised. Then take a break and repeat. Worked really well for me. Try it.
https://en.wikipedia.org/wiki/Pomodoro_TechniqueBreaksTake regular breaks to walk about, exercise, socialise etc. Breaks will keep your head fresh and help it to retain information better. I got A*AA and I found time to hang out with friends and exercise. I read books and played chess in some of my free periods.
Keep your head clear.Ask questionsBig one: Use your teachers well.
Do not be afraid to ask questions, that's what they're there for. You don't have to ask in the middle of class. I went to my teachers at lunchtime and after school to get help on certain questions/areas of the course.
You have to
be honest with yourself on what your weaknesses are or it'll be much harder to get the marks in the exam. Everyone has questions but not everyone asks them! This proved useful for Bio and Chem for me.
Following on, if you're good at something then put it on the back-burner and
focus on your weaker areas. Keep the good areas ticking over (i.e 15mins each day doing questions, reading over) and then dedicate the core revision to areas where you are weaker.
Past-PapersI did
PPQs from Start to finish and then started doing full papers closer to the exams. Do as many questions as you can.
Examiner's reports are a free gift from god, use them and find out what areas people consistently make mistakes on.
http://pastpapers.org/, This site provides legacy papers for lots of exam boards. You'll want all that you can find.
PlanMake a plan. This helped me a lot as well. Even if you don't follow it religiously, at least you'll have a good idea in front of you on what areas you should be focusing on and not neglecting.
Revising 2/3 hrs everyday starting immediately will do wonders for you later on.