For maths, just do past papers and then topic questions on your especially weak areas. that's all you can do for math revision since notes are the biggest waste of time. use youtube videos for bits you're completely confused about
for RE I did the same thing for english.
for bio and chem I just memorized (quite literally) the textbook and did a few practice papers nearer to the deadline to get a gist for the type of answers/phrasing they're looking for
basically in summary
essay subjects = writing and remembering key quotes
humanities & social sciences= remembering key dates, case studies and remembering structures
Sciences and maths = pure memorisation of textbooks and practice papers
also, if you really want a good english grade, do essay questions at home and ask your teacher to mark and criticise them so you can see where you're going wrong.
hope that helps
another fun fact: genius lyrics has some decent analysis of poems which can act as a basis for your essays