How do you find a good Sensei/Master to teach you Bonsai?

It doesn’t take a lot of searching on the internet to find a legion of sites that claim to be able to “teach” you bonsai. YouTube in particular is peppered with such sources, some of which are extremely good but many of which fall very short of the mark in terms of the tuition given. This is often because the videos are poor quality, or because the presenter is not good at public speaking. Even worse, however, are the rather many sites that give the viewer information that is quite simply wrong.