The Writers' Program Quarterly of the UCLA Extension program includes some interesting quotes about pitching.
Here's what Chrysanthy Balis, writer of the film "Asylum" among others, says about how she prepares for a pitch: "I write out a treatment, sometimes only five pages long, and sometimes up to twenty pages long. When I have finished getting the story to a place where it shows a real vision for a film--having hammered out all the important turning points and major plot beats--I then condense it to bullet-point format, outline style. Now comes memorization and rehearsal time. Using the bird's-eye-view that the bullet outline provides, I put on my "fireside storyteller" hat and rehearse an engaging, conversational delivery of the story, hitting not only the major story beats, but making sure that I draw them into visualizing the story cinematically."
Notice how much work goes into something that--if done right--will appears casual and effortless to the listener!
More on this subject soon.