You can teach someone how to back up a trailer in a few minutes with the easy to remember rule about turning the wheel into the mirror that the trailer shows up in. You will never lose control of a trailer as long as you remember this rule.
Same goes for teaching basic flight control. You will never cork screw a model into the ground if you know how to keep the wings level. The LHS owner had me soloed on a 6 foot span glider within a 1/2 hour, thanks in part to teaching me this simple rule about moving the stick to whichever wing panel is low as the plane heads back to you. He trimmed the plane so that it had a slight amount of down trim [your throttle with a glider] and had me fly big laps around the entire field while I rehearsed every upcoming turn out loud to him. He gave random advice about pitch control, etc. It was our goal to see how long each flight could last and to not force any issues for where I landed the plane, just as long as the landings were into the wind all was AOK with him.
I used this same approach to teach both my sisters and my son how to fly.
Before any hands on training is done, the basics of what makes a plane fly and of what makes a plane stall and crash need to be explained.