Main point is it's common to practice wrong. It's hard for non-experts to assess expertise, needed to find a coach to give feedback. Though, probably for a be

Main point is it's common to practice wrong. It's hard for non-experts to assess expertise, needed to find a coach to give feedback. Though, probably for a beginner in many fields, an even minimally credentialed "expert" will be extremely helpful. (This is apart from fields lacking agreement on advice, like the article's public speaking example).