I'm lucky - my club has a training night Thursday of each week during the summer. We have a half dozen or so instructors that show up around 3 and hang til dusk. Sometimes we have 10 or so students with all levels of skills. Our phone numbers are also published on our website so students can call for other days. I happen to like to instruct with my own equipment so that that variable is not variable. When it comes to other's equipment I get nervous 'cause I'm pretty anal about setup but I will fly it with them. Ya do what ya can.

Btw, kinda fun watching someone with skills take some unfamiliar plane and make it dance in the sky. Show's the student what is possible with their plane.