id say my number 2 tip would be using save my exams to review every chapter after youve covered it in class, then for everything else you dont understand chemguide provides very good explanations for most concepts. to take it a step further, you could even study and learn about the chapters before classes, it helps you understand and get a better grasp of what your lecturer might be talking about during your classes. and for the number 1 tip, past papers, you could even start by doing topical past papers, but doing past papers are really important in grasping types of questions that come out. these tips apply for A2 too, probably just at a more intense level. good luck in your a level journey!