"No, but" versus "yes, and"

I was listening to a talk the other day, and the speaker was talking about how she preferred "yes, and" phrases to "no, but" phrases when talking about someone's ideas.

In general I favor this approach too. Conversation that builds up rather than breaking down is energizing and encouraging. But you can't only use "yes, and." Sometimes you want to disagree or criticize. The speaker seemed to think that even in those situation you could/should cast what you're saying as a "yes, and." The exampl...