If you must inconvenience anyone, it's good manners to apologize to them.
Always offer to teach others: sharing your knowledge is just plain good etiquetteand fun, too!
Proper phone etiquette: If your phone call interrupts a date, keep your conversation brief and to the point. Also, it's polite to inform her when you're on the phone!
If someone is interested in a new experience, always welcome them to try it out.
Can't remember a person's name? It's acceptable to address them casually until you remember it.
Gambling: it's just plain wrong.
Always say "please" and "thank you."
Don't exclude others from activities! Be sure to involve everyone in what's going on!
And perhaps most important: never, never let The Kingpin use a salon hair dryer. This isn't exactly "proper etiquette"...but it's a darn good idea under any circumstances.
Panels from Captain America #146 and 147 (February and March 1972), script by Gary Friedrich, pencils by Sal Buscema, inks by John Verpoorten, letters by Sam Rosen