Okay, you've got a really complex subject that has a lot of "hard" facts to remember... and there's an exam coming up.
You know you are going to have to remember that formula/definition/date, so you write it down on a piece of paper and read over it as often as you can - saying it out-loud to a mirror to help you memorise it.
But it's so very similar to another formula/definition/date that you have to remember for the same exam, and you aren't sure if you'll remember exactly which one is which when it comes to the crunch...
While memorisation is great, and learning things by rote can really help you recall things later on, the best thing you can do to remember something is to engage with it.
If you know what that formula does (and what happens if you change one part of it), if you use that definition in context, if you remember something else that happened on that date... well it might mean more to you. When it means something to you, you stand a better chance of remembering it.
One of the best ways to engage with the facts is to make something out of them. Anything at all.
It could be a study guide for a Sixth Grade class, which makes you rethink the way you present the information so that twelve-year-olds can understand it. It could be a series of slides created for your own class - as if you were going to teach your peers a lesson on the subject. It could be a short story in which the facts form crucial plot points. It could be an interpretive dance, in which each movement represents a core concept.
Whatever makes you happy. Play with it - come up with something that gets you not just thinking about the information but actively using it.
This also helps you work on an important skill - synthesis. It's one of the higher order thinking skills Bloom lists in his taxonomy, and it can help you improve the quality of the work you produce.
When you make something new with the facts you have on hand, you're more likely to remember them later, and more likely to be able to use them effectively.