This extremely prolific writer has won numerous awards, including the National Book Award. She writes in longhand, and while she doesn’t have a formal schedule, she says she prefers to write in the morning, before breakfast . She’s a creative writing professor, and on the days she teaches, she says she writes for an hour or 45 minutes before leaving for her first class. On other days, when the writing is going well, she can work for hours without a break — and has breakfast at 2 or 3 in the afternoon!

I love James Joyce's response: three sentences!!!
There is a lot to learn from these people on the discipline front, at least for me in writing!

Writing every day is the main thing I think.