Challenge your own way of thinking and let other traders help you uncover your blind spots. We all have them. I'm looking for people who think differently than I do so I can learn. I don't have a monopoly on ideas and I can be a bonehead at any given time.
I rely on systematized trading rules and by gaining new insight from other people (who are mostly much more intelligent that I am) I am better off because I can oftentimes reduce the wisdom into a trading rule to enhance what I already have.
I couldn't do that on my own - not without a great deal of random luck or perhaps a big loss that helped reshape my thinking. Below is a partial list - there are more coming.
David Aferiat - Trade Ideas
Tadas Viskanta - Abnormal Returns
Steve Sears - Barron's Striking Price