I remember asking a new high school friend how he knew so much interesting stuff and his answer was "I listen to people." That really wrinkled my brain and I've been a listening evangelist ever since.

One of the big traps I try to avoid, and I see other people make often, is focusing on making a particular point even if the conversation is flowing away from it being relevant. Stay in the moment.

Also, don't try to use conversation to prove how smart you are to the other person. Take a genuine interest in talking to them and getting something out of it. I have a relative who just uses conversations to shoehorn in all of his favorite talking points, even though we all know them all already and it only detracts from the discussion.