How do u get A*

No matter how much effort I put in, I usually end up with a D or C.
I’m sure many others feel just as frustrated as I do.
You might not fully understand, but please—if there’s a way to learn effectively so I can achieve at least an A or B, let me know.
I’m studying A-level Chemistry and Biology, and I spend most of my free time at sixth form trying to improve, but it seems impossible

I 100% agree with the response above, you can also do a bunch of past papers, especially for Biology as they are picky with wording, because this helps exam technique. Also, by doing past paper questions you are revising and cementing the knowledge you've learnt and may be able to spot how certain questions want you to answer them

Get help from your teachers - that’s what they are there for! Regularly go to any extra revision sessions or clinics if they run them. After school, pick a topic you find hard and ask them for specific advice on the parts you don’t understand and ask for resources that will help you learn and practice those parts. Then do them. Show your work to your teacher and ask for more advice on what you have done and what you could do next. Use their help. Ask questions and get their help during lessons too. This is your learning and your A levels, so push yourself to get the support you need. Ask and learn. Ask and learn. Ask and learn. Don’t be shy!
My daughter finds chemistry tricky but likes to ‘blurt’ to revise it. She has a large whiteboard and writes/draws everything she can remember on that topic and then reviews it after. Obviously past paper questions are excellent and really trying to understand the mark scheme is invaluable - you need to be able to use the vocabulary and structure that the examiners need to see to be able to give you points, so past papers and mark schemes are your best friend.
Make a revision product while (or as soon as you have finished) studying a topic, so it is fresh in your mind. Then file and store that product in an organised manner so you can access it again sporadically to review and before exams. Products like mind maps, summarising, online or physical flash cards etc. Good luck

Thank you! Really apreasate sharing this information with us all.
I think I shall start trying out mind maps as. As I didn't try them before

Pleasure
I might also add that having a good sleep routine helps a lot (I noticed you posted at 4am!)
Obviously ignore that if you are in another country and there’s a time difference or if you are Muslim and waking to eat before sunrise because it’s Ramadan!