The best anecdote I heard about that was the guy (wish I could remember his name, but he was interviewed by Matt on Freelance Transformation) who found that it was much easier to quote a high rate if he had a cigar in his mouth because it made him feel like a mogul :-)

I'm guessing that was on the phone...

This has made a huge difference for me because I'm a terrible negotiator. Earlier in my career when more hinged on negotiation and I needed money, I sometimes worked for small fractions of what I could have.