1. Get a stopwatch or timer or some sort. Anything that will pay attention to time for you.
2. Get rid of all distractions that you can control in your writing environment — turn off your cell phone (not just to stun, but OFF), turn off the TV, turn off the iPod, etc. Create as much silence as you can.
3. Choose the method of writing that is least distracting for you — writing by hand, on a computer, a manual typewriter, whatever. (Well, maybe not texting.) If you’re on a computer, get rid of all distractions — no email, Facebook, etc. If you have a program that allows fullscreen writing, go into that mode.
4. Turn on your stopwatch or timer and start writing. What you write doesn’t matter. But keep writing. Push through those difficult first moments where you don’t know what to write. Push yourself. Keep going.
5. Stop when you absolutely can’t stand it any longer.
6. Write down the time you see on the stopwatch.
7. Write at least 500 words about this experience. How long were you able to focus on nothing but writing? What finally made you stop? What did the experience feel like? Looking at what you wrote now, what do you think of it? What would allow you to write for longer? Etc. Really delve into this experience and what it tells you about yourself.