You should study by practicing paper 4.
Things you should DEFINETELY study:
1. Formulas (obviously!)
2. Function graph (never came in paper 2)
3. Sequences (never came in paper 2 and which I detest)
4. Percentages (usually the first question in each paper every year)
5. Probability (never came in paper 2)
6. Cummulative frequency / statistics (never came in paper 2)
7. Mensuration (surface area and volume questions - never came in paper 2)
8. Transformations
Can't think of anything else right now but if I do I'll post it.
Did I help/
Hope so cos I racked my brain for you!
Rockstar:
Are you doing the IGCSE exams?
How will it help you if you get to know the paper after we've done it?
I'm really confused with your post.