Hey I did the same subjects as you and am currently in med school. For biology I made my own notes. Initially I only used the textbook and my teacher’s notes. I then condensed everything and reworded. As I revised for topic tests, I used the past papers I did along with the mark schemes available to refine my notes. The same question comes up again and again and sometimes all you need to do is list some key sentences to gain all the marks. For example: if they ask for the process of DNA replication and it’s 5 marks you will only need to remember key bits of the process: enzyme names, unwinding, complementary base pairing and any valid points etc etc. So really to get an A* in biology you must understand concepts (don’t memorise), do as many past papers as possible, and learn exam techniques (oh and use the textbook but avoid over reading. Textbooks tend to put irrelevant but interesting facts). For chem, revision is a lot easier. I got all my notes from chemrevise and added mark scheme answers. I watched Allery chemistry for extra help and did all the IALs, AS level and A level past papers before my final exam. Build a strong year 12 foundation to ensure a smooth year 13 transition. Chem content gets progressively complex as you follow the course so be sure to master the basics (all topics intertwine). For maths the one way to revise is to simply do all the past papers. It’s worth making notes on how to answer certain questions: especially for mechanics and statistics in year 13. Make note of any difficult questions and copy the mark scheme down. Exam technique is another thing to note. Since the same question types come up again and again, learn what steps are necessarily needed to gain marks. One tip I have is to never cross out your working as you can gain marks by simply showing correct procedures without having to obtain the correct final answer. I also watched full paper walkthroughs on YT for when I can’t seem to make sense of mark schemes. Hope this helps!