Remember how the parents are depicted in the Peanuts cartoons? All you hear is “wah wah wah wah”… and sometimes I think the kids hear adults like that. It’s probably worse after a long day of school even if always present.
A lot of the other tips also revolve around showing: the diagrams are a quick step but using physical depictions or demonstrations are even better.
Having a player demonstrate what you’re saying as you’re saying it, and explaining how you want people to play relative to each other by stopping action during a scrimmage rather than trying to lecture at the beginning of practice.