Teach your teens to: Blame you.
Why it works: Kids who can truthfully say, "No, I can't -- my mom said she would ground me for life" have a crucial advantage when it comes to saying no to their peers, according to researchers from the White House Office of National Drug Control Policy. But that means parents have to tell kids, early and often, exactly what the rules are, and what the consequences will be if they are broken. Be as specific as possible. Say, "If I catch you smoking, you will lose your allowance and be grounded for a month." "If I find out you drank, you will lose the right to drive our car." "If I learn that you've had sex, I will chaperone every date you have until you turn 18." Knowing the consequences ahead of time makes it easier for kids to stay safe.
Teach your teen to: Make "no" funny.
Why it works: Many times teens do say no, but in a way that creates unnecessary social problems. "People who expect to be taken seriously don't have to whine or yell," says Borba. A kid who makes a joke when refusing, saying, "Sorry, I'm trying to be less popular" can stay out of trouble and still save face with peers. The one who says fearfully, "No, we might get in trouble" risks being branded a lifelong wimp.