Last month the Vicar and I spent some Nectar points on a garden swing. Sitting on it is incredibly relaxing but we had to make some rules about usage by children as we anticipated that over-vigorous swinging might ensue.
So the rule is:
You can only sit on the swing seat IF YOU ARE READING
This is working very well. I occasionally break the rule myself, but as it’s my rule I think that’s okay. Sometimes I just sit there with the Vicar or a friend and talk. But today the kids were on the swing, obeying the rule, which I found very heartening:
Reading (from L to R) Dr Who, Roald Dahl and Harry Potter
The Vicar's Wife 
What a great idea. Maybe they should install swing seats in Public Libraries?
Looking forward to trying it out. Will remember to bring a book…
What exactly are Nectar points?
Excellent rule. If they all continue to want the swing at once, provide them with a book of plays (Shakespeare might be a little heavy at their age, but what about Christopher Fry?) and make ’em read all the parts in turn???”)”)