Keep it simple. Dialogue tags—he said, she said, etc.—are usually all you need to indicate who’s speaking, so resist the urge to get creative and overdo it. Mentors and teachers who tell you to do otherwise and find alternatives are, more often than not, unpublished and believe agents and publishers will be impressed. Believe me, they won’t be. Avoid mannerisms of attribution, such as wheeze, gasp, sigh, laugh, grunt, or snort. Your characters may react in this way while speaking, which you could mention, but the emphasis should be on what is said. Readers just need to know who is saying it. You need to keep it simple or your creativity may overshadow the actual dialogue.  If it’s important that if your character sighs or moans, you separate that action from the dialogue. You will still see it occasionally, but I suggest avoiding these, as they can come across as cliched. Only use dialogue tags if the reader would not know otherwise who was speaking. 

Another common mistake is when characters address each other by name too often.

In the real world of dialogue, this rarely happens. If you want your characters to be believable, then your dialogue must be realistic. Always end your dialogue with an attribution tag and not at the beginning. Resist the urge to tell your reader how the character is feeling, believe me, they will not appreciate it. Give the reader credit to work out the mindset of your characters themselves. 

An amateur writer will sometimes write something like this: “I’m beat,” exclaimed John tiredly.

Besides telling and not showing, you are breaking a cardinal rule of writing by using the archaic exclaimed for said, misplacing that before the name rather than after, and adding the overused tiredly. 

The professional novelist would write: John dropped onto the couch. “I’m beat.”

That shows rather than tells, and the action, dropped onto the couch, informs the reader who’s speaking.

How to Punctuate Dialogue

Few things expose a novice writer like incorrect punctuation, especially in dialogue. Agents and publishers understandably wonder if you read the dialogue, let alone whether you can write it.

Common mistakes to avoid:

When dialogue ends with a question or exclamation mark, the dialogue tag following the quotation marks should be lowercase:

 “I’m glad you’re here!” she said.

If one of your character’s dialogue is longer than one paragraph, start each subsequent paragraph with a double quotation mark, and place your closing double quotation mark only at the end of the final paragraph. Place punctuation inside the quotation marks, the dialogue tag outside: “John was just here asking about you,” Jim said.

Put the attribution after the first clause of a compound sentence: “Not tonight,” he said, “not in this weather.”

If there is an action before dialogue, a separate sentence is required: Anna shook her head. “I can’t believe she’s gone!”

Finally, every new speaker will require a new paragraph. 

For example:

Rosie sat shaking her head and telling him all the reasons his plan would never work. Rules, regulations, protocol, procedure, no exceptions, and the list went on and on. “I’m not going to help you with this, Bobby.”

“Yes, you are. I know you too well.”

“You don't. Have you been listening? It’s impossible…”

“But you’ll try.”

Rosie rolled her eyes. “I wouldn’t even know where to start.” 

“Sure you would. You know everything, and you’ve been working for the company for a long time.”

“Bobby, don’t ask me to do this.”

“I’m asking.”