This is an interesting question, but I worry that people overestimate the value of "teaching teaching". Most people who've been trained in sales or leadership

This is an interesting question, but I worry that people overestimate the value of "teaching teaching". Most people who've been trained in sales or leadership know how much of that training is useless. The techniques work fine for the teacher, they might work fine for someone else in the class, but they don't work for you. It's a fundamentally social, interpersonal task, and so a method that works for one person may fall completely flat for another. The teachers I know generally describe something similar. A full day of staff development might produce one good insight, and it's not always clear which tip is good and which ones aren't going to work for you. My best teachers have shared certain skills, but they've also taught with vastly different formats and techniques. Training helps, and all of them were experienced teachers, but attempts to "export" advanced teaching skills almost always fall flat.