These days, for my insomnia, I'm listening to Walter Isaacson's Benjamin Franklin: An American Life. I've just come across Franklin's list of "conversational sins". It's good. (I'm afraid I've committed them all.)
1. Talking overmuch
2. Seeming uninterested
3. Speaking too much about your own life
4. Prying for personal secrets
5. Telling long and pointless stories
6. Contradicting or disputing someone directly
7. Ridiculing or railing against things, except in small, witty doses
8. Spreading scandal
Notice how beautifully the list coheres with personaliism. Genunine interpersonal communion, of which conversation is a major aspect, involves a transcendence of the ego, and an attention to, interest in, and care for the other. All of Franklin's "conversational sins" are cases of being too ego-centric or of treating another in a way that misrespects his personal dignity, or both.
He also has some very good positive aphorism for good conversation:
"Knowledge is gained more by the use of the ear than the tongue."
He began to make use of "silence and gentle dialogue."
"Soft, socratic quieries."
"Deferring to others"
"Understanding, not victory, should be the aim of disputation."
Can we think of any others to add?