While working with kids here in school, a good advice was given by our Associate Head. This advice is to "Turn the negative into positive". When you see that a boy who's being naughty and misbehaving in class and tell him "John, be quiet and behave yourself" or "John, seat properly", normally they will not listen to you or if they do, they will do it again in a couple of minutes. But if you said something like, "Wow! Look at Mary, she's well behaved in class." or "Wow! Look at how Mary is sitting, she's got a good posture." This will have a great impact in the class and they would also behave properly and sit up straight. This advice doesn't just apply to kids but also adults. If we reward good work or give a word of praise for a job well done, others in our business will also follow suit and do a good job.