If you've asked your child to do something and she doesn't, repeat yourself up to one time, and that's it, Rabbi Shmuley says. If you constantly repeat yourself, you become a nag, he says. "The last thing you want to do is become a nag, because they tune you out and avoid you," he says.
If your child still doesn't listen, point out the consequences. For example, tell them "I told you to clean your room once. If you don't do it this time, anything left on the floor is being given to charity," Rabbi Shmuley says. "The third time, don't repeat yourself," he says. "Follow through with the consequence and make sure you do what you said you would, otherwise you have no cache in the house."