My ad agency years taught me never to show clients work that, for all purposes, couldn't be released as is.
Showing anything less than finished work gives clients little to evaluate. And showing anything less destroys the magic.
So I was gratified to hear an actual magician, Teller, express this principle to the host of NPR's This American Life.
Teller describes how he labored for months to incorporate the legendary "floating ball routine" into Penn & Teller's show.
Teller worked alone at night on an empty stage in a darkened theater, week after week, testing move after move after move, to make the trick fresh. He tested different props; built a stage set; abandoned it, and built another.
Only when he'd perfected the routine did Teller show it to his partner.
"Why didn't you just show Penn something rough?" the host asks Teller. "Just something with the moves you'd been inventing?"
"No, no, no!" Teller insists. "That's the thing about magic. You can't look at a half-finished piece of magic and know whether it's good or not. It has to be perfect before you can evaluate whether it's good.
"Magic is a fantastically meticulous form. Magic is an on/off switch. Either it looks like a miracle or it's stupid."