see the impression they are leaving.  I do it through humor.  Sometimes it works, and sometimes it doesn't.  When it doesn't work and I'm really not in the mood to play nice, I do turn it back on them a little.  Nothing wrong with letting some one have a dose of their own medicine every now and then.  Ofcourse, being a mother, I have to point out that this was my deliberate intention.  

My older son, who is a bit scowl-y, usually chooses people to associate with who are very different.  I think that says something.  I'm very glad that his girlfriend is a lot like the females in our family.  Its as if he's trying to somehow make up for what he considers less positive features about him self.  I think part of him recognizes that this really isn't how he wants to be.  And a little reinforcement from sources outside the family isn't a bad thing.