So far we've talked about actors as art school models and dancers as art school models...that leaves only one more category that needs to be covered....
A good teacher will bring props to class that might heighten the effect: glasses, funny wigs, fake buck teeth, etc.
I've already mentioned this but it bears repeating: nothing I've suggested is meant to displace classical figure drawing. The picture above makes an eloquent for the classical approach. I just think cartoonists would benefit from both kinds of model drawing.
BTW: here's a fascinating animated short about art models. Many, many thanks to Kelly Toons for the link!!!!!!!!!