Revising for exams, or rather, mugging, requires an extensive use of short term memory. I was, somewhat, maybe a little more conscious of the amount of memory I was using this time round. I guess, it's mostly because I wouldn't be able to do the exam questions had I not remembered the exact formula required. Anyway, I did surprise myself with being able to have a rather good rate of recall of the formulas. I only hit the full steam of memorising the night before (for an exam the next morning), and when I woke up, all of the stuff I memorised was still there. So that's just like an hour or two of committing the material to memory, and there's almost perfect recall. (I didn't forget anything in particular during the exam either).
I'm not sure if this is due to having a good night's sleep. For the record, I did roughly 6-7hrs (it varied) each night. Studies apparently show that memory and recall is enhanced after sleep, so maybe it might have been that effect. The other thing I did was to try to couple a bit of emotion, or strange quirky ways to memorise things. (Here's a tip: if you're really desperate to memorise something, shout it out loud and let the embarrassment help you recall whatever you shouted out.) I then used the really quirky way of remembering it to tell my friend about it, who would then laugh and comment about how weird is the stuff I come up with. And it helps! I remember it better after that, simply because I had told my friend, and he laughed at it. It makes it much easier to recall something if an emotion is associated with it, or something at least deeper than just the fact itself.
I think I ever posted about using songs to collate your memories and as a "indexer" so that if you hear the song again, all the memories associated with it start to surface. But this method here is a shorter version, and probably easier to do. It's difficult to always try and think of something quirky and unusual though, so I'd recommend only using it if you're really needing it, or your mind just happens to generate it at the random spur of the moment (this usually means that you'll remember it better as well!).