Dialog is my favorite part of writing. Probably because I'm good at it and people tend to enjoy what they're good at.
If I'm at a loss about how to start a scene, writing the dialog is my go-to response. I may go back later and write an opening for the dialog, but the dialog is often the first thing I write. I've found that dialog gives me the rhythm of the scene. It shows me the characters' state of mind and the direction the scene will go. For me, the story takes shape through the dialog.
As an added bonus, the characters sometimes reveal things to other characters through dialog I didn't know about them. It's a joy to let them talk to each other. It's even better if they're talking to cross purposes. But even better than what they say is what they don't say. The secrets they keep.
Protecting those secrets, whether they're rooted in fear, ego, shame, or any of the other emotions that cause us to hide who we are, can lead to arguments, and that's conflict, which are what good stories are made of.
So when I reached the place in the climax of my WIP A Dark & Stormy Knight where my heroine has privately faced her fears and is ready to own up to her mistakes with her ex-husband, I was shocked when the dialog was lackluster and boring. I couldn't even get a good argument started.
It turned out that the problem wasn't with her side of the conversation, but with his. Even though she's ready to own up to her mistakes, that doesn't resolve their estrangement. Emotionally, she wants the answer to a question she should have asked twelve years ago, but none of his possible responses worked. If he said, "Yes," everything resolved too easily. "No," wasn't even an option because it destroyed that illusion so vital to romance that they are meant to be together. I even tried "I don't know" (which I still think is the most realistic answer), but that was too wishy-washy for a romance novel.
My solution turned out to be having him say yes, but letting her not believe it while he focused on her failure to ask the question before they wasted those twelve years. What neither of them focus on is the question that really needs answered: What would his response be today?
This decision turns the climax into a two-parter, which seems much more satisfying to me, because it's unrealistic to have him say the things I want him to say unless he has time to think it through and come to his own set of realizations, just as she has.
But what my characters say isn't what I enjoy the most. It's the things they refused to say before the climax. The things the reader knows they feel but that the character is holding back in an effort to protect their most vulnerable sides. They have to expose that soft, white underbelly eventually, or the character arcs are unsatisfying, but holding back on that makes them feel more real and increases the tension.
At least, that's how I hope it works.
So what sort of things do your character leave unsaid?