While I do not have a daily routine, nor am I by any measure famous, I can identify with Susan Sontag:
I write in spurts. I write when I have to because the pressure builds up and I feel enough confidence that something has matured in my head and I can write it down.
And E. B. White:
A writer who waits for ideal conditions under which to work will die without putting a word on paper.
Thanks to Jake Runestad for finding this article.