There isn't one best way, because different people learn and remember in different ways. You may need to write everything down, for instance, or make graphs and charts, or you may find that you are an "aural learner" – you remember things better if you hear them , so in that case you should say key words aloud or make up chants.
Once you've worked out how your memory works best, there are some tips for revision that should work for everyone:
-take lots of short breaks. About 50 minutes is enough for a burst of study, followed by 10 minutes to move around, have coffee etc.
-eat sensibly and don't study all night; your brain works much better if you're well fed and alert.
-have a study plan. What are you going to tackle today? this week? It's really best to think exactly how many days till the exam, and note down a study idea for each.
-start early. It's ALWAYS later than you think.