1 : marked by polished manners, gallantry, or ceremonial usage of a court
2 : marked by respect for and consideration of others
Charming people focus on the other person. Rarely are they themselves the topic of discussion. Be nice to others. If someone is excited or wants to discuss a subject that you have no interest in or have a negative interest in; say nothing. (Granted this would be in relation to entertainment issues, not debating/argument issues.)
In most cases, arguments are meant to be persuasive. Take a moment to think about that. How persuasive is an argument that automatically makes the other person wrong? Are they going to be receptive to your point of view? What are you really trying to accomplish by directly challenging another person?
Avoid talking down to people. If you're never wrong, you're always wrong. You have to give ground occasionally or risk losing the respect of people you're arguing with.
I think someone needs to look up being courteous again. They're a little confused.