Nobel Prize (2008) winning Economist Paul Krugman has written about how he works and lists out his four basic rules of research which I think is applicable to every knowledge worker around:

1. Listen to the Gentiles - "Pay attention to what intelligent people are saying, even if they do not have your customs or speak your analytical language."
2. Question the question
3. Dare to be silly
4. Simplify, simplify (Thoreau's amxim is timeless)