1.  Don’t start the conversation with “We need to talk” or call a “family meeting.”  Starting the conversation this way immediately puts up their defenses. These statements usually precede very difficult conversations and are interpreted as “Oh great, I’m in trouble again.”
2.  Don’t drone on and on trying to drive your point home. LESS IS MORE!  I recommend what I call “the drive by method,” just quickly and casually say what you want to say and then just leave it. Maybe even leave the room. This will trigger your teenager to give some thought to what you said. THE MORE YOU TALK, THE MORE DEFENSIVE THEY ARE GONNA BECOME!
3.  Don’t jump on every ridiculous statement or plan that they express. Most things teenagers say change in about 5 minutes anyway so there is no reason to start World War 3 over it. For example, if your kid comes home and says “I’m gonna be a tattoo artist,” don’t freak out (at least not yet). Just say something more ambivalent like “wow, that’s an interesting choice, you are pretty creative.”  Just wait to see what ideas stick and which ones disappear before you call a family meeting and give your 4 hour lecture about why that is a bad idea.
4.  If your kid is verbalizing some sort of problem or concern, DON’T GIVE ADVICE UNLESS THEY ASK FOR IT. Think about the last time someone gave you advice without your asking. Most of the time we jump too quickly into advice giving without a full understanding of all the mitigating factors. It’s better to be empathetic and curious. Being empathetic will calm their brain, and asking curious questions will make their brain move into problem solving mode.
 
5.  Don’t blame the “bad influence friends.” Every parent thinks that their kid is a perfect angel and they are being pressured by outside forces. Hold your kid accountable for their own choices. Blaming their friends is counterproductive for several reasons: They will defend their friends even more furiously than themselves, It’s sending a message that they aren’t responsible for their own choices. It makes you look really naive.