As long as we're on the topic of breaking, what's the best way to progress from a beginner's stage?
In the arts I've practiced, breaking was never a part of the training, and any breaks I've done were because I knew I could do it. However, I've always been curious about it, especially with the different breaks I've seen.
Easiest way to start them, is to have them break a single 1' x 1' square of soft pine, that has been dried well. Have them start with something easy, such as using an elbow strike, or a palm heel strike. Once they're used to this, have them try other techniques, such as straight punches, kicks, etc.
Once they have enough confidence, put another board on top, with some spacers between them. Have them go through two boards. Watch their eyes open as they realize, that it's easier than it looks.
Eventually, you can have them try speed breaks, but make sure that you use a dried out, white pine board here as well. No sense in letting them injure their knuckles.
Later on, you can use 2" thick cement slabs (again heat-dried), and start with easy techniques, working your way up. Low risk techniques, such as hammer fist, work well.