This is an old paradigm I was taught early in my coaching days to teach skill. What is neat about it is it encompasses all styles of learning, auditory, visual and kinesthetic.
Tell them – Make it brief and to the point
Show them – Make sure you show the whole action, then the key parts and finish with the whole action
Do it! – Have them do it, do the whole action at a controlled speed, then some part drills, then the whole action