Instead of thinking I have to write a novel, or a story, or even a paragraph, I say, what is one thing that has happened to me in the last seventy-two hours that glimmered at me in that particular way that says, write me down?  It might be something very brief, a line of overheard dialogue, a particular way light was reflecting off of some Aspen trees. I'm not going to write, I think to myself, I am just going to record this momentary thing so I don't forget it. More often than not, once I have done that I am off and running.  

Alternate answer: Read Beloved for the twentieth time.

See answer to one above. But to that seventy-two-hour glimmer I would add two more: one from at least five years ago, and one from any time at all.

"As important as how you tell a story is how you avoid telling it."  — Francois Camoin