My favorite writing teacher Anne Wylie provides practical tips on the writing process in this article. 

I'll add that when you're just shoving copy around on a page, it's time to take a break and change the channel in your brain.  Check your email, toss the frisbee for the dog, walk around the office, get some coffee or water, exercise, or talk to someone and you'll stimulate the flow of ideas. But, enough from me; here is Anne's advice – and see how cleverly she promoted a business offering?