Last week one day our older son was complaining about what I was cooking for dinner, complaining that he never gets to eat what he wants, complaining, complaining, complaining.
I asked him to list ten things he is thankful for. He told me “no” and was promptly sent to timeout. His condition for release was to complete the list. It took some time for his “I’m not going to do it” attitude to transform, but after several minutes passed, he decided that he didn’t want to remain in timeout indefinitely. The first two items on his “thankful” list were toys and desserts. At one point he got stuck and needed a bit of prompting – a few more ideas from his parents to which he agreed he was thankful. A bit more whining was also a part of the process, but he did come up with ten items. And we enjoyed a pleasant complain-free dinner together after that.
first teacher 
I ought to try that with my 13 year old!!!
Let me know if you do. I think it could work with any age.