I do Geography, psychology and Art.
1. Make flashcards --> 2. Learn flashcards --> 3. Practice questions/past papers --> 4. Mark and identify areas of weakness --> 5. Repeat
I try and make my flashcards as I'm being taught the content so I stay on top of it. When it comes to learning them, don't worry about exactly memorising it all but instead getting a good understanding of the content. I use a combination of topic-specific questions and general past papers, best under timed conditions. Once you've marked the questions, identify the areas you need to work on and prioritise these topics, going over your notes/flashcards again and then sit another past paper to not only ensure you've improved but also to make sure you haven't slipped in the other topics.
-Little and often and gradually build up - when I first was told I would be sitting mocks, I started doing just 1 hour of revision a night and then slowly increased it to 2+ hours closer to my mocks.
-Push yourself but don't go OTT - try to avoid procrastination as best as possible but acknowledge when revising wouldn't be sustainable - if you're really unmotivated and exhausted then take a night off because forcing yourself won't help
-Ask your teachers for specific areas to improve on, they may not provide anything helpful or they might mention an exam tip you haven't thought of yet
-Reward yourself and take breaks
-Make a plan and stick to it - for example, set yourself a given topic each session that you'll focus on
-If you're struggling with learning a process (for example, I find this when learning the endless processes in Bio) diagrams are really helpful. I just use the Paint 3D app on my laptop and create a rough sketch. When I'm doing my flashcards on that process or get a question on it, I can visualise the diagram and it helps me remember it
I hope this helps, and good luck with your studies!