The best way to revise is by doing active recall as this ensures you'll remember the information. This could be from flashcards, mind maps, blurting or whatever else works for you.
For English lit, depending on the texts you do, I recommend Stacey Reay on YouTube. Her analysis is detailed and unique so her videos helped me to get a grade 9. For English lang, practice questions are useful because they allows you to understand how answers are structured. It's best to do practice questions in timed conditions (this goes for all subjects) so you're prepared for the exam. For both English lit+lang I recommend looking at exemplar answers/essays so you know what your exam board are looking for in answers, which will allow to you apply those techniques in your own answers to get the most marks.
For GCSE science, flashcards were really useful for me as there's quite a bit of content to learn. Blurting could also help you find any weaker areas in your knowledge. Freesciencelessons and Cognito have good videos on YouTube for going over content. Also, practice questions are a must as well so you understand the mark scheme.
With History, once again flashcards helped me as there's a lot of content. I also made a lot of essay plans as they helped me to understand the structure of different questions. It's important complete full answers as well (in timed conditions) so you are able to cope with timings in the exam.
Maths is all about practising. The more questions you do, the better prepared you will be. If you're struggling in any topic area, GCSE Maths Tutor and Maths Genie on YouTube have videos on specific topics and they go through plenty of worked examples. The Maths Genie website is also an excellent resource as they have worksheets that are separated by topic, and the topics are separated by grades so you'll have a rough idea of what knowledge you need for what grade. I also recommend the Corbett Maths 5 a Day: it's 5 maths questions a day (there's different 'packs' based on difficulty) and it's a great way to ensure you're doing as many questions as you can.
I hope this advice helps. If you have any other questions, I'd be happy to answer the best I can