How you revise or want to revise shouldn't really be consistent with every subject due to differences in content and style; it may be helpful to specify particular subjects for individual tips.
English/History/Psychology, etc: It sounds a little obvious but practice writing essays. Post them online or give them to your teachers to review and practice timing conditions and creating plans that you will stick to (they suck but are helpful!). For English Lit, I mainly used youtube videos. Literally type in the poem and find an analysis and it will give you more then enough information you would need for getting an A*.Also I've head that reading outside of your comfort zone, even if it's just a new book or a broadsheet newspaper is useful in developing your language. The minute you've mastered the art of writing with purpose, throw in some more developed or sophisticated language. Oh and make sure your spelling, punctuation and grammar are pretty decent too.
Maths/Science: I cannot stress how important past papers are for these types of subjects. Exam boards are lazy and recycle questions to the death! Invest in a good revision guide as well; those tend to be pretty useful in learning main points and you can replicate diagrams and create mindmaps to stick around (which will help you remember). If you're a video kind of person, examsolutions for maths and crash course or khan academy for science are pretty good - require lots of dedication to sit through each of the videos though.
Geography/Citizenship/Religious studies: These subjects I saw more as remembering facts and then just dropping them into specific questions or essays. Basically just learn to regurgitate information. (I recommend using flash cards when revising these types of subjects)
Languages: A good textbook and good relationship with your teacher will help you out a lot. To become fluent, you need to learn how to inject your vocab into everyday conversations. Talk to the mirror or the wall if you have to!
Drama/Technology/Food tech: These subjects look more at developing and perfecting a skill. Literally practice makes perfect in this case! Just be confident with what you're doing and in your own ability.
ICT: Being friends with a techy person wouldn't hurt. This one is a little hard to give advice for as it depends what you're specification has asked; some just want learning basic skills, others want website creations, etc
Music: Come up with a decent composition, practice for the performance as much as possible and basically memorise the textbook.