Chris I would have to write a whole article on this in order to answer your question.
I was lucky enough to be part of an innovative practice spearheaded by the most talented leader as a principal. She herself is worth a post! .
We were rigorously inserviced by leading lights in the field, We'd come back as a staff, test, reconnect and massage and come up with our agreed principles and practice.
A group of us was co-opted into two teaching universities. The groups we taught would then come into our classrooms and see things in practice.
They, the students, declared the sessions to be the best experience they'd ever had.
Working in that school was the best time in my teaching career.
Teaching is not an easy job. It's hugely complex if you really think about it.
Having a degree is the first step in competence, and I would always guard against a fledgling teacher being on their own. They need mentors, various mentors with different skills to share.
I'm sure there are many people who are born teachers, but we have to be careful that we don't reduce teaching practice to that of delivering a how-to. Or, going back to post-war days where someone was quoted as saying, 'I've been teaching for five years and I'm not even certified'.