Over-using character names within dialogue: don't do it

Dialogue-writing tip: don't overuse characters' names within their speech. For example:

"Would you like some eggs, Dolores?"
"Melvin, you know I'm allergic to them."
"Are you? I'm sorry, Dolores, I'd forgotten."
"It's all right, Melvin. But please pass me the toast."

In real life it's basically only annoying people in sales who keep using your name that frequently in conversation. Or your parents or significant other when they're annoyed with you. So if that's not the point you're trying to make,...