I would say for myself mood plays an important role. If I'm not in the mood to write, the computer screen will stay blank for hours. The sun helps me with my mood. I can write a whole book from April-June and then spend July-September editing it. Then fall comes along; the dreary, cold weather moves into New York, and I'm at a standstill. I even tried fluorescent lights on my table to mimic the sun, laugh at me; it's fine, but of course it didn't work. It only made me hot and caused black spots to dance along the blank computer screen instead of words. I admit it; it was cool, but I would rather words, sentences, dialogue, anything.
With that being said....how do you get over the hump of a blank computer screen?