Organize your work!
- have a paper notebok and an electronic agenda (notebook as "lab-journal"/for scribbles/meeting minutes/..., the agenda for dates/reminders)
- as first action of every day: write down what you want to achieve by the evening (and keep track)
- priorize unsolicited interrupts (now, later, never)
- add notes in your code (//TODO...) and keep track
- read your email/facebook/twitter/... only once a day, e.g. in the evening before leaving
- stay focussed
Depending on your life style and where you live:
- reduce/stop inhaling/drinking/... legal/illegal drugs ;-)
- sleep and drink enough (oh well, that's my sinn ;-))
I don't say that I do all for that in a strict sense ;-) - sometimes I also fall back into bad habits :-(
But in general, they are useful tools for me...
BTW: you might ask why *paper* notebook? I have tried out many other (electronic) tools. The outcome is that you are less effective with electronic tools in real life: you don't have always your tablet PC/slate/iPad/... with you, scribbling on a display is still too distracting/little intuitive, you get papers/business cards that you can simply "fold" into your notebook (and later firmly attach if really necessary), others can write scribbles into your book as part of pair discussions/design/sketching/... Once it's full, I archive them (pile them up) with all papers in it.
Sounds anachronistic, I know, but its the tool I came back to again without regret.
PS: Never ever copy anything from the notebook to the PC - that's complete waste of time (except for reminders).
PPS: To quickly see while browsing through your notebook what is scribble and what is to-do: have for each to-do a circle drawn in front of the to-do - with a textmarker highlight the perimeter of the circle if the to-do is open - fill out the circle with the textmarker, once the to-do is closed.