How do I teach a friend how to be a Spotter?

Awag1000

Interstellar Research Systems
Supporter
Full Member
Minuteman
I've been bringing a friend to the range to be a trigger puller so I can work on my own spotting skill. but my idea of working as a team has both the spotter and the shooter basically on the same level skill wise. both He and I are decent behind a rifle well out to 500 yards, but I'm not sure how to go about teaching him how to use a spotter's scope or make windcalls. any help with this?