I use most of ZTD (http://zenhabits.net/2007/11/zen-to-done-the-simple-productivity-e-book/). GTD is too sophisticated and to big for me.
Basically, I make lists of tasks. Every morning I select three which I really need to do that day. I work on them until they're done. I struggle not to get dragged to other things.
In an office, I sometimes book a conference room and work there, distraction free. I emerge from the lair when I'm finished with the three most important tasks.
