You're gonna laugh, but here's a couple tricks I do that help:

1. The paper brain - I carry a small pocket notebook in my back pocket, and take notes on everything that goes on during my day, giving the most detail to the things that seem most important.

2. Lists - Make a list of stuff that needs doing today. Stick to that list. (I title mine 'stupid **** I gotta do today'. This also comes in handy when it comes time for evaluations for raises and such - you can 'blow your own horn' about the things you've accomplished.

3. Knock out the mundane crap you hate doing worst, first. This takes the part of your day away that just sucks, and leaves you free to enjoy the rest of it.

4. Get up a half hour earlier. Amazingly enough, that extra 30 mins spent over coffee and breakfast (yes, eat!) will get you fired up for the day. Don't spend that half hour whacking the snooze button or you're defeating the purpose.

5. Get your lazy arse to bed earlier. If you normally stay up till round midnight, you're losing valuable sleep time. Sleep is non-accumulative, meaning you can't go all week on 4 hours a night then recharge on the weekends... Get your butt in bed by 9:30 or 10:00, and get a decent sleep.

6. The biggest trick of all, and the one we work hardest to accomplish: The 'doesn't apply' or 'teflon man' rule. - Make things not apply to you. The less **** that sticks to your fur, the less mess you have to clean up later. If something happens that applies, handle it in a prompt manner. If something happens that doesn't directly apply to you or your specific job, for God's sake keep your hands out of it and your mouth shut! You'd be amazed at how much time we spend fixing other people's foul ups. By making things 'not apply' you'll be quietly steaming away in your own job, fixing your own foul ups, and not worrying about others - and you'll free up about a half a day depending on where you work and who you work with.

[edit] I decided to expand a bit since folks seemed to like the Teflon Man thing -

If someone wants you to do something that 'doesn't apply', explain to them politely how it doesn't apply to you, and either politely refuse, or if you have extra time, add in what a scum they are for imposing on you and how they owe you a HUGE favor at the herculean efforts it will take to accomplish this (petty I hope) task, then do it. You'd be amazed at the good perks that'll start flowing your way. It landed me a wife. [/edit]