I've taken lessons at a variety of levels and my general almost across-the-board recommendation would be to talk less when on the snow and show more.
I understand about different learning styles, etc., and I am a verbal person in general. But excessive explanations while sitting on the side of the slope just don't do if for me.
Also, yeah I realize that sometimes goofy images work and stuff, but other times I want an actual strategy. In other words, when I've requested a lesson in the bumps, don't tell me "imagine you're water trickling down the hill," tell me instead "I want you to try hitting the bump 2/3 of the way up its side with the board flat, then pivot fast. Here, let me show you."
Sooner or later your legs give way, you hit the ground.