Speak to the class as a whole about bullying. Explain how hurtful it is to the person being bullied. Explain that bullying is never allowed and those who bully others will be punished. Have regular talks about bullying to remind the class that it is never acceptable.
Teach the children how to respond to bullying. For instance, if a child sees someone being bullied, he needs to know that he should immediately tell the teacher.
Pay attention to the whole class to get familiar with the regular behavior of each child. If an outgoing student suddenly becomes quiet all the time, find out why. Make sure she is not being bullied. Let her know she can always speak to you.
Arrange seating assignments carefully. Keep children who have been picked on or teased away from children who have bullied them.
Enforce rules against bullying. Follow through with the appropriate punishment.
Speak to the bullying child's parents. If the child continues to bully, her parents need to be involved and work on ways to stop the behavior.