1. First, set up to-do lists for different contexts (i.e. calls, computer, errands, home, waiting-for, etc.) depending on your situation.
2. First thing in the morning, work on your most important task. Don’t do anything else until this is done. Give yourself a short break, and then start on your next Most Important Task. If you can get 2-3 of these done in the morning, the rest of the day is gravy.
3. Plan your day in blocks. You might try one-hour blocks, or half-hour blocks, depending on what works for you. Maybe try 40 minute blocks with 20 minutes in between them for miscellaneous tasks.
4. Have something to write on close by (such as a notebook) for instant notes on what needs to be done.
5. When you are working on a task in a time block, turn off all other distractions. Shut off email, and the Internet if possible. Try not to answer your phone. Focus on that one task, and try to get it done without worrying about other stuff.
6. If other things come in while you’re working, put them in the inbox, or take a note of them in your capture system. Get back to the task at hand.
7. When a task has been completed, mark it off your to-do list. The gratification of crossing off a finished job is indescribable.
Businessweek did a great piece on a man who tried to stop multi-tasking for one week. Check out that article here!