Be friendly, respectful and polite towards others as default. On the unusual occasion you encounter a ****, deal with it diplomatically.
Act in a way you would like the world to act, trying not to get dragged down to the level of the ****.
When meeting people, try to remember names, ask about their lives, and only talk about yourself if relevant/prompted.
Celebrate your strengths without getting arrogant. Be honest about your weaknesses without getting getting self-pitying.
I try to stick to the above with varying degrees of success. I can still be a **** at times.