You may also want to develop a password or code word known only to your child and you. If a child is approached by somebody and told to leave with him or her, the child should not go unless the person knows the password. Teach them there are things that adults should never do. Talk to your child about setting boundaries. No one can touch a child's body without their permission just as they should not touch another person's body without that person's permission.
Children learn best when there is repetition.
Practice how to be safe as often as you can. Keep the lines of communication open and above all else, listen to what your children tell you. The offender, not the victim, is responsible for the abuse.