The night before the exam with a jar of coffee beans and a soup spoon to eat them with......
lol.
Seriously, I make summaries with the syllabus. Things like stuff on the groups, key features, and I make sure I have definitions of all the concepts (eg. militarism, communism, etc).
For dates, I select the important ones and put them on flash cards to learn them. It makes it fun (not lol).