Not on the nose, please.
Conflict is essential in effective crime writing. I like to create conflict in my dialogue by keeping it oblique. For instance, it’s amazing how much tension can be generated simply by banning yes and no (and their synonyms). Try it at home or work, and you’ll soon see what I mean. There’s nothing worse than dialogue that’s a series of questions and answers. Particularly in an interrogation scene!
Don’t just talk; do something.
I also like to break up speeches with action. Three sentences are about as much as I’ll allow any character to utter in one burst. I then break off to let him scratch his chin, or, better still, interact with his immediate physical environment, and only after that will I let him continue speaking. Inserting a visual cue helps keep the reader grounded, develops a sense of place, and also provides variety.
Ideally, if a character is given the right words, syntactical choices, body language, actions, etc., there’s no need for the writer to interpret his emotional state for the reader. Consequently, I rarely use any verb other than said to carry dialogue. Also, I use adverbs with caution. If there’s a choice between telling us he’s angry or showing us how his anger manifests itself, I’d always recommend the latter. For instance,
“I don’t much care for adverbs,” he fumed, angrily.
is less effective than,
“Adverbs stink,” he said, slamming his hand on the table so hard the plate rattled.
Okay, I lied. Don’t use said.
Lately, I’ve been using constructions like this one more and more:
“Don’t move.” John aimed his weapon at the burglar. “Or I’ll shoot.”
Avoiding dialogue tags entirely is a challenge, but it’s worth pursuing. It focuses you to be more visual, to show your characters interacting with each other and with their world. Often, using dialogue tags is simply a way of breaking up the dialogue (sometimes unnecessarily), and banning it forces you to be more creative in how you achieve that. And as James M. Cain pointed out in the introduction to The Butterfly, “Why all this saysing? With quotes around it, would they be gargling it?”
You say tomato, I say tomato. Or maybe banana.
It’s horribly easy to end up with characters who all sound the same. Yet no two people in real life share the same vocabulary or speech patterns. We all have certain words we prefer, even if we grew up together (an all-too-common excuse for having similar-sounding characters). The words our characters use help to define them. So it pays to have a few words or expressions in mind that each character is particularly fond of. Ideally, a reader should be able to tell who’s speaking without having to be told. A tough ask, I know. I continually struggle with this one.
Dialogue is a heavily edited version of real-life speech. It pays to treat any clumsy, repetitive, dull, long-winded, inessential parts just as you would any other aspect of your writing. If there’s a word or phrase (or longer) that you can cut, then hit that delete key.
“As you know, Bob,” is not your friend.
Getting information across in dialogue can be tricky. Here’s an extreme example of how not to do it:
“As you know, Bob, I shot you last week. I hope the titanium rod inserted in your shattered tibia gets you back on your feet in three months, just like Doctor Shadwell promised.”
Readers rarely need to know as much as we think they do. And if we can get the information across visually/obliquely/dramatically, so much the better. We don’t need to know exactly when Bob was shot, or that he has a titanium rod in his tibia, or that it’s likely to be about three months before he’s back on his feet, or even that Doctor Shadwell is treating him. Any and/or all of that information — should it be pertinent — can be revealed later. The following gives us as much as we need to know for now, and because we don’t know the whole story, it has the advantage of being intriguing:
“Suppose I better get used to this.” Bob eased himself into his wheelchair, leg stuck out in front of him in a shiny red cast.
“Could be worse.” Pete bent down and looked him in the eye. “I was aiming for your belly.”
Fragments are your friends.
Finally, watch out for characters who speak in sentences, especially sentences with subclauses. They only exist in fiction!