heyy!
i'm in year 10 so idk how useful this advice will be to you
biology - I find that compared to the other sciences, biology is very content heavy, and usually the mark scheme requires you to give very specific/detailed answers. So maybe, you could start by learning the key concepts/main points, by maybe making notes, watching freesciencelessons videos etc. Then, you could do some practice on seneca/cognito to see if you understand the main points, and to identify any gaps, which you can go back to and revise. I know that the first thing some people do is make flashcards, but I usually like to save making these until after I've actually understood the topic bc there's no point making flashcards and testing yourself on content you don't fully know. The last thing I usually do is exam question, bc as I said earlier most of the marks are awarded by mentioning specific things that are on the mark scheme.
useful resources: physicsandmathstutor website, mmerevise website (you can get worksheets of specific parts of a topic you don't particularly understand), seneca/cognito as mentioned
maths - I think the best way to do maths is just to do past paper questions over and over again under timed conditions, and if there's a specific topic/question you don't know or want to know the method for, you could always watch a runthrough of a past paper on yt.
useful resources: corbettmaths website, mathsgenie website, or just anywhere you can get past questions
geography - I'd say geography is also particularly content heavy, and there tends to be specific detail/information required in questions, so maybe maybe you could make summarised notes by watching yt videos, reading a textbook, online resource etc. You could also draw diagrams with key words/pictures to help you remember them better. And I find that making flashcards on things like key processes, statistics, fieldwork etc can be useful (but it's up to you what you want to make flashcards on). Oh another way i forgot to mention, is also making mind maps or using revision mats. You could also do specific exam questions under times conditions eg, the 8/9 markers.
revision resources: (again) mmerevise website, bbc bitesize website, physicsandmathstutor, yt vids on key processes
re - I can't really say much for re, as i'm not the best at it. But i would definitely recommend watching revision vids and using bbc bitesize to make sure you understand everything first, then you could make notes on it. You can also make flashcards to remember quotes and stuff. And similarly to geography, you could do mind maps/brain dumps, (just writing out everything you know, then look at the specification, and anything you've missed, you can do some extra work on.
revision resources: bbc bitesize, seneca, any yt vids
just some general advice: i recommend having the specification at hand whilst your revising, so you can see what you actually need to learn and to make sure your not learning anything more than you need to. Also make sure you do exam questions, as questions are often re-used, and just make sure you use a range of revision techniques to see which works best for you!
again, idk how useful this advice is to you, but i hope it helps, even if its just slightly!!