I meant to add this time management rule to my previous Fall Review post. I can't remember whether it originated with Mark Forster or David Allen, but it goes something like this: At all costs, avoid heroic efforts to get things done. Examples of an heroic effort would be pulling an all-nighter or shoving all other obligations to the side to totally focus on The One Project that needs to be done by tomorrow morning at 9 a.m. As I said in the Fall Review, yes, some projects do need hours of uninterrupted time so you can make progress. But I think the ideal is that you plan that work well ahead of time -- staging its component pieces in the days leading up to it -- so that you can approach the work or project mindfully rather than in a panic. And, so you can leave your desk at a decent hour feeling that you're on top of things and get a good night's sleep.
Forster's "little and often" and "continuous revision" rules can help here if you start early enough and if you're consistent in applying them.
Unfortunately, because I had not used my time wisely on Sunday (I chose to work on a project whose deadline was further out and I underestimated how much time the looming project actually needed), I had to launch an heroic effort on Wednesday to meet a Thursday deadline. This effort took 8 solid hours of time and attention and I was left quite depleted afterwards. And it's the aftereffects, the post-partum hangover, from an heroic effort that must be avoided. It can take a while for your tanks to refill; in the meantime, other projects are backing up.