Revision for gcse

If u got a 9 in ur gcses can u tell me what did u do to get it pls

The biggest tip - do past paper questions and mark them (harshly). GCSEs are just about knowing mark schemes and knowing how to tailor your answers to mark schemes (especially for the sciences). This is the most important thing. For essay subjects, do lots of essays and essay plans and give them to your teachers to mark.
Apart from that - revise that subject like you're planning on taking it for A level. So don't just do the assigned work, do all the homework, the challenge and stretch tasks, do some independent research about the subject as well. I also really enjoyed doing this as it made me like the subjects more (like in biology for example, I watched a documentary about HIV, AIDS and double-blind trials). For history, I studied the course more in depth than the textbook went, and also watched documentaries and read about topics that technically weren't within our specification but I still used them as relevant examples in my exam (history was my highest mark).
The only exception to this was maths, where the best method of getting a 9 is just practice, practice and more practice.