«Pay it forward tree» is a good way to stimulate the kindness and tolerant behaviour. On a huge leafless tree the teacher will add leaves with the names of students, who has done a good deed. For every five /or ten/ leaves placed on the tree, a flower is then added. This is a visual representation of kindnesses shown within the school community. Children could also be asked to give out leaves to teachers they see being particularly kind.
For older students: Every time a teacher observed a student doing some act of kindness, whether it just is a kind word or a courtesy, he/she would write a CERTIFICATE for that person and display it on a board.
Photos from «Pay it forward tree» in Greece
«Pay it forward tree» in Italy