From Rachel Toor's "The Habit of Writing" at the Chronicle:
"I only write when I am inspired," Faulkner apparently said, and added, "Fortunately, I am inspired at 9 o'clock every morning." Most of them say that you need to take writing seriously, to treat it like a job.
That's probably good advice. It just doesn't work for me. For me writing has become less a job than a habit.
A friend who wanted to start running said that he'd heard it takes three months to form a habit. I don't know whether that's true. It sounds both facile and pseudoscientific. But over the years, I seem to have performed a trick of mind, managing to convince myself that getting up every day and going someplace to write was as normal as brushing my teeth, making my bed, or watching reruns of House. Whatever psychological move I used, it seems to have been successful.
And in the comments, a quotation from Philip Glass:
In my student days I knew a lot of composers, many of them more talented than myself. But I learned one thing most of them did not: good work habits. When I was still a teenager, I forced myself to write music during a set period every morning, and I also forced myself to stop at one in the afternoon. I refused to take down musical ideas at other hours, even when they came to me. You might say I trained the Muse to come calling at my hours, not hers. And it worked. For years now, I have gotten my ideas in the mornings and never in the afternoons."
Now back to work.