Even if I'm only presenting a handful of slides I'll slap some blank ones on the end just to make everyone sweat over "Slide 1 of 83". Everyone is pretty darn quiet and glad to help speed things along most of the time.

Do you give presentations to people on whom this works more than once?

Ya got to mix it up, sometimes you really do have an 83 page slide deck.

Don’t forget the random slides of pet photos.