Help your teen find peer groups and activities that promote healthy, positive behavior. Give your child opportunities to interact socially with peers in a healthy, safe environment. If you know your teen is lacking in social skills, help her develop them. For example, teach her how to introduce herself to others, smile and shake hands - as well as speaking up for herself when she feels uncomfortable.
Encourage healthy friendships and discourage unhealthy ones. If your child is drawn to friends you don't approve of, try to talk to your child to find out why he enjoys their company.
Make sure that you approve of your child's friends and know their parents. Be aware of their online "friends" as well.