Five steps for coaching people:
1) Tell people what you want them to do.
2) Show them what a good performance looks like.
3) Let them do it
4) Observe their performance
5) Praise progress and/or redirect
Managers most often miss the fourth step: Observe.
They give directions then clear the area. If they don't stay around to watch, you have no data with which to do the last, most important step: catch them doing things right, or else redirect their efforts.