What subject is the exam on?
Each person is different so what works for some people might not work for you. Cramming used to work for me sometimes too. Everything else I just had to put the hours in and work through it.
Checklists help - write down each potential topic that could come up on the exam. At the start note down if you're confident, okay or shaky on each topic, so you can identify your weakest areas and start with those. As you study, keep using the checklist so you cover all areas, so you'll hopefully have a good grasp of everything.
Making quick posters for each topic helped me too. Not only do you learn writing everything down, if you do everything in different colours you'll remember where on the poster the information was and what colour it was, which can aid with recalling the information itself. Writing these out early means that you can keep going over and over the information. If there's a lot of information you may have to spend a day doing these but once it's down, you've got it to use constantly afterwards.
If it's an exam where you can do practice questions then definitely go over some of those. You can definitely learn by doing, so go over the questions to help you understand the processes involved.
If there are any lists that you can make with a certain order then that might be beneficial too. Remembering an order to something can help you remember all the points.
Finally, if you can study with a friend or ask someone to test you, do that. If it's a friend who is doing the same exam and if you've made posters, give them half the posters and test each other on each half, then swap posters. Then you're going over the same information twice in one sitting. Go through everything and then go over it again a little while after. Keep doing this over the course of this week whenever you can.
I think repetition is the key, so hopefully the more you go over the information, the more it'll stick and the better you'll do on your exam. Obviously all these methods won't be suitable with certain topics, but I hope I managed to give you a few ideas. Good luck, and let us know how it goes!