
Whether on stage, screen or in a book, dialog is just another part of a performances intent on entertaining an audience. Right? So you can follow all the rules for writing good dialog, but if the delivery is forgettable, the reader won't hesitate to trade in your novel for another selection.
To further my point, when you read these quotes, what do you hear and see in your mind’s eye?
"You talkin' to me?"
“I coulda been a contender.”
"E.T. phone home."
"...Bond. James Bond."
"I'll be back."
"Go ahead, make my day."
"Here's looking at you, kid."
"There's no place like home."
"You can't handle the truth!"
"I see dead people."
And the list goes on...
Even though each quote is only five words or less, I personally heard the character's voice and relived the background scene from each movie, and I'm sure you did too.
Dialog comes to me in the voice, personality, accent and tone of the character as I write. From there, I show what's going on around the dialog, striving to create moments for the reader that are just like reading one of those movie quotes. If I can create even one moment as memorable as Judy Garland clicking her heels and saying, "There's no place like home," I'll go to my grave a happy writer.