Winding up for the pitch

Pitches are baffling to me. Or rather, the construction of pitches. Sure, there are formulas all over the Internet on how to craft the perfect pitch, but I think I’ve made clear how much stock I put in those hard-and-fast writing rules. Although I did come up with a pitch forĀ Demon’s Heart, I have far less practice writing pitches than I do writing novels, so creating the perfect pitch seems to me like trying to catch a fly with your bare hands, except that once you start trying you realize that your hands are duct-taped to your knees and, come to think of it, you’re not even really sure there is a fly.

So I’m appealing to the greater knowledge and experience of the Internet to see if I can at least get the duct tape off my hands. When do you form your pitch? Early in the writing process, or are you like me, where you get to the end and think, Crap, I have to sum this up in one sentence? Do you practice your pitch? On whom? How do you get feedback? Have you participated in any of those Twitter pitch contests, or any other sort of pitch contest? What was your experience?