Mind maps can be a useful revision tool, helps you visualise topics you need to cover and allows room for any diagrams that are relevant to the topic. However, in my experience I've found that mind maps can be limiting with how much I write- and I tend to oversimplify by bullet points which didn't really help me.
As Biology tends to be one of those 'memorisation' subjects, I found that flashcards worked for me best. I would look at past papers, and search for those big 5-9 mark questions and have those written down. The question on one side, and the mark scheme on the other side. This was really helpful as it structured the answer in a sensible manner, and already has the key points and keywords that would get you the mark. Using flashcards for definitions helped me drill it into my brain more too! If you find certain biological processes or sequences difficult to remember, you can try create a mnemonic that would help you.
Physics wasn't really my cup of tea but when it came to calculations, I typically did a bunch of past paper questions and practiced the maths that way as that was my area that needed improvement.