Avoid gestures like shrugging your shoulders or leaning back with arms folded, which a kid is likely to read as, "I don't accept you." And don't stand above her if your teen is sitting or is shorter than you, sit down.
Beware the scowl, the raised eyebrows, the rolled eyes, the smirk. They don't like it any more than you do.
Skip the heavy sighs and groans. You probably do it without even realizing.
Are you talking to your teen in the voice you'd use with a friend? Keep it casual and conversational.
If you're not careful, your voice may go up a level. Moms need to use their "indoor" voice, too.
Talking too much
Bite your tongue literally if necessary. Count to 10 and give your child plenty of time to formulate his thoughts.
Don't try to be funny; hypersensitive kids may feel insulted. Save your sparkling wit for grown-ups.
Stay as relaxed as possible, even if you have to say, "I need some time to calm down. Let's talk later," and come back when you're cooler.