I, personally found it helpful to write out notes from my revision guides into a notebook and make revision cards. I learnt my definitions by making flash cards from them and then matching them up and I learnt my formulae by writing them on revision cards in coloured pens. Once you have revised all of the stuff you need, you need to do Past Papers as this is the best way to prepare for an exam
These techniques helped me to get 2 A's in Business 1 and 2 so hopefully they will help you, everyone is different though! Keep trying different ways of revising it until you find a way which suits you!