Biology honestly two things changed my life when it came to biology.
1) biology with olivia books, you have to pay for them but i swear to you its well worth the money
2) revise topics not in spec order as spec order is so random. Revise topics as they relate to eachother across the whole spec. For example revise protiens and then revise enzymes and then revise different topics that have enzymes in it like dna replication (3.1), atp (3.1), digestion (3.3), mrna (3.4), restriction enzymes in the final part of the spec (3.8), rubisco (3.5) and yk the list can keep going cos theres so many enzyme stuff.
The reason i say to revise topics as they link rather than spec order is because it helps soo much with essay when doing the AO2 but also the way the exam is structured is youll have like this year a,b,c) was triglycerides and then d) was to do with lipid digestion and e) was to do with phospholipids in phagocytes. Something like that. But itll help you to understand and answer questions better as well.