(This is slightly related, and really interesting; I'd say it's worth the hour, but for an excellent precis go here.)
I can't grind revision. I haven't done that much in the way of "proper" revision, certainly not in the making-up-notes-and-going-over-them-agai
Related to this, I only seem to remember things I'm actually interested in (I recently discovered I'm humiliatingly bad at the geography of the British Isles, because while I've probably been exposed to plenty of county maps I've never really given a damn.) I am quite lucky, I think, in that I still love War Studies and find it fascinating, while a lot of people I know who've taken their subject to degree level have come to hate it. I'm far from conscientious about reading lists; I don't grind through the books because I'm supposed to, I read them because they interest me. I like to think that helps, because I never remember anything I've learned "on demand". Forcing myself to learn, through grinding notes, or picking up a book I don't care about, just doesn't seem to work as well; it doesn't stick.
Detail is a funny bugger. I have a head for detail - especially pretty finicky detail, especially that to do with weapons and mechanisms - but that I can give you a description of the inner workings of every weapon involved in any battle since 1860, is, while interesting, irrelevant, because there's no way to bring it all out in an exam. Judicious use of detail adds texture, believability, historical verisimilitude, but that's all. Toby advised us to try to give the impression of an iceberg: enough knowledge to make the tip of the iceberg, used adeptly enough to convince the examiner of a much broader and deeper understanding beneath the surface. There's never enough time or enough space to show off every last tidbit; drop a few appropriate facts, confidently, and be damn sure they're true.
I think what matters most in history is understanding the broad sweep of the topic, not so much what as why, having a picture in my head which is detailed enough to be believable but abstract enough to be understood in its entirety, so that a question with unexpected phrasing or which picks on an unexpected part can be dealt with. And I find getting bogged down in the minutiae, especially too close to the exam day, is actively counterproductive to that.
I believe that ultimately - and I'm staking quite a bit on this belief - what works best is demonstrating that I understand that broad picture, backed up by enough fiddly detail to sound authoritative. That understanding is something I can only seem to get by thinking about the subject at length, and having the space and the time to do so, unencumbered by piles of frantic notes.
Disclaimer 1: Different people's minds work in different ways; many of my friends have very different approaches, which seem to work for them. This particular way has worked for me, for writing a fairly small number of widely spaced essays, and a novel(la). Applying it to a real subject, something that requires genuine factual knowledge rather than eloquent prevarication, or something that actually matters, may result in waste and tragedy. When the GDL kicks off I'm going to be doing a lot more grind and some serious personal re-evaluatin'.
Disclaimer 2: That this entire post is basically a smug, self-serving and generally despicable post-facto justification for my pathological laziness and "brief, blinding panic after sustained, intense procrastination" approach has, yes, crossed my mind.