For Chemistry, I guess reading and understanding before taking notes are the prerequisites. DON'T take any notes from the books when you understand nothing and when you understand nothing, you can't take relevant info from the teachers either. Do, read the topics until you understand it adequately to catch up with what your teacher will lecture before going to class. When taking notes, creating a mind-map is not a bad idea and diagrams are suitable. But I think when you can internalize the lessons at the first time you encounter it then it won't take too much time to revise the lessons without even taking notes.
Maths: of course the more you practise, the more deeply the formulae are carved in your mind. Quite simple.
English: commenting in this forum will help! lolz
So, notes are good for some but not all. If you find memorizing your notes is too difficult, change it! Like some other people suggest
draw pictures and stick them on the walls or everywhere you must go to at least once. [not implying the loo]
discussing with friend is the most effective way I have to say,
explaining to someone else is also good but you'll find it boring soon when that audience doesn't give a sign of having some idea (that's frustrating)
Remember: as long as you truly madly deeply understand the lessons, you have no difficulty when retrieving it. If you find it hard, start from the beginning 'cuz otherwise you can be confused between concepts and explanations. Don't try to re-understand st 'cuz actually you have never made it yours, you've just assumes it!