I always have a clock in front of me. Sometimes, if things are going badly, I will force myself to write a page in a half an hour. I find that can be done. I find that what I write when I force myself is generally just as good as what I write when I’m feeling inspired. It’s mainly a matter of forcing yourself to write. There’s a marvelous essay that Sinclair Lewis wrote on how to write. He said most writers don’t understand that the process begins by actually sitting down.