Rookie Mistakes --
General mountain dulcimer or music discussions
Your lesson should be about more than just a strap. It's what some folks call "situational awareness". Always be aware of where you and yours are in space at any given time -- what and who is around you, entering and leaving your space; what is near and far; static and in motion. Use all your senses to hear, see and feel what is going on around you -- even while you are concentrating on playing dulcimer or talking or whatever.
Fortunately, or unfortunately in this modern day and events, those who practice situational awareness tend to be survivors -- of dulcimer accidents and other things.