Review your notes everyday so that you are up to date with everything going on in a course.
Practise a lot of past exam questions. Practice will help you understand the subject even better.
Make sure you understand everything. Seek help to clear the slightest doubt you may have.
Be consistent and work till the very end. Don’t get overconfident. There are always new things to learn till the very end.
Don’t panic! Be calm. Enjoy And relax every now and then.
Understand what is happening. Pay attention in class and again, practice a LOT of questions !!
Practise a lot of multiple-choice questions. Questions are very often tricky. And they do repeat. So the more you practice, the better.
For paper 2,4 again practice makes perfect. Try to complete as many past papers as possible and time yourselves. Paper 4 can be quite challenging.
For practicals and planning (p5), don’t panic in the lab. Be calm and focus. Pay attention to the small details (eg colour change, smell...) during your normal school/tuition practicals.
Practice is the key.
Personally, working on past papers (before year 2000) tremendously helped me in understanding physics and the concepts better.
Read your books. There are much information that are very helpful in books. Notes from school or tuitions can be concise and books will give you much more information.
Try to do at least one essay question every week. It sucks (especially if you hate GP, just like I did) but it is going to help you. And make sure to complete the question within the time allowed.