I first posted this advice from my cynical history teacher 2 years ago, but it still holds true today:

Take notes on all the notes you've taken on lectures, discussions and books throughout the year.

Take notes on your notes.

Then takes notes on your notes of your notes.

Continue until you a left with one paragraph... then one sentence... then one word.

Careful not to show it to your friends. That would mean they were cheating.

And if you forget the word?

Zen would have a re-assuring punchline. Personally, I wouldn't bother to sit the exam