for subjects like maths go through each topic, chapter by chapter and make sure to make summary notes with all of the formulas etc and example questions and stuff so that you know the processes for everything and can memorise the formulas easily (good for cramming before exams). then once you've done that PAST PAPERS galore.. or well really for all of those subjects do as many past papers as you can for all ur subjects!
Ancient, Eco, Business go through dot point by dot point and make sure you know the content first.... the only thing is to write notes on everything.. yes even if you already have... do them again and again and make summaries of ur original notes until you've rmemebered everything and can get it all down to a few pages suitable for last minute revision.
English you just need to understand the content and then practise and prepare essays for all the modules... go through with teacher and mark and assess how u've done.. prepare excellent intros and make sure you understand the concepts. practise on improving your writing style as much as you can to make it perfect.
nothing more than practise practise practise