Honestly, I'm just applying stuff as preached by Customer Development & Lean Startup. I highly recommend those. Ash Maurya's Running Lean has some good conversation "templates" too. What I bring to the table here is not anything new that nobody has already talked about. What I bring here is the actual physical act of picking up the phone and applying those methods.

In a nutshell, I call someone up in the target market, within that first 15 seconds give them a reason why they shouldn't hang up on you, then get the actual conversation started to see if they have the problem, and if they're interested in a solution .. giving them the opportunity to object (you won't learn what the objections are if you keep trying to convince them otherwise).. and you'll either make a sale, or learn something new that you should think about addressing in the solution, or just in the way you pitch the next person. I'm not really doing any justice here, CD and LS covered this extensively!