Go to an old-style movie theater where you can tell which are the people coming out of the feature you wish to see. As they file past, make a guess about their personal qualities. Possible guesses are "immature," "pretentious," "dopey," "sad sacks," "not very attractive," and so on.
Then pick up the mirror, so to speak, and start believing that you hold this same quality more than you used to think you did.
I played this game last night at Bergman Island (recommended, the best part is when he calls bad conscience "a petty conceit"), with distressing results.