I introduce the children to the feelings that we get from when someone does something nice and call it ‘warm fuzzies’ and the opposite feelings for ‘cold pricklies’.
I also draw the children’s attention to the fact that when they get a warm fuzzy given to them they want to give one back (i.e. a smile), and this also goes for cold pricklies (ie how a fight starts). I then get the children to make clouds with their own warm fuzzies ideas written on them (such as; playing a nice game, or making up with a friend) and spikey shapes with cold pricklies on them (ie; hitting someone, or being called a name).
I make a display of these and label them the land of cold pricklies and warm fuzzies. The children have a bug, each with their name on, which begins in the land of warm fuzzies (as I trust them to keep to our class rules already in place) and if they do a cold prickly thing, they have to move their bug themselves to the cold pricklies land. I have slots of 5, 10, 15 and 20 labelled with those numbers, and this corresponds to the amount of special/golden/choosing time they lose.
They can move up again back to fuzzy land if they do fuzzy acts. Works a treat!