In studying with tutoring students I have found that writing down what needs to be studied on index cards is a great tactic for memorization for those who are experiencing difficulty in memorizing events or vocabulary. This can also be applied for any subject matter. The process of writing down the facts of an event, definition of a vocabulary word, a formula, etc. is what helps memorize the material.
Afterwards, you use them as flashcards to go through all the material you need to study and can better measure how much you have actually learned/memorized. I often use this tactic myself in my law courses in which I have to memorize hundreds of Supreme Court cases and their facts. This has proven to be the best way for learning the subject matter for me and has helped me personally succeed in my education.