Sandy
describing the nymphing techniques and then to get someone to do it properly is a bit difficult.
Not impossible, but difficult.
I have a Nymphing Masterclass I do in SA, where the numbers are limited to 8 fly fishers for 2,5 days.
Even standing next to a person, 1st showing him a technique and then getting him to do it CORRECT, takes a lot of personal tuition/coaching/demonstrating, with me next to him on the water.
But we can try.
(sometimes more harm can be done, by learning the wrong things, instead of the right things)