Tip #39: Step away from the screen...sometimes.

I think it's a real misconception that writers are only working when they're writing. In fact, I'd argue that most of my best and difficult work is done AWAY from the computer. What really helps me is to go for a run or walk the dog and just let my brain go free.

http://www.allisonwinn.com/ask-allison/2011/1/11/combating-writing-blahs.html