She's trying to find a way out

She can't even whisper, much less shout

She's lost in a manmade hellscape
With no way out

- Action beats are just as useful as dialogue tags in contextualising who is speaking and how. 

- Avoid exposition in dialogue unless it fits - and even then, be cautious about info-dumping. 

- Characters can lie or omit information from others in dialogue, so use actions to demonstrate their true intentions. 

Don't write exactly how people talk, because that's not entertaining, but don't be too theatrical, because that feels forced and unengaging. 

2. People talk in different ways, represent that

People are different, and have different speech patterns and little habits when they speak, try to represent that in your dialogue

3. Avoid infodumping

Show, don't tell. Don't present all the information at once, put it here and there in the dialogue. 

4. Be awkward

People don't take turns patiently to talk, they interrupt each other, forget what they're saying, etc. do that when necessary, it helps establish your characters as actual humans.

5. Be brief

Very rarely do people ever go into a long, interrupted monologue when talking to another person. That doesn't mean characters can't go on for a while, but show that the other character is listening. Include a "mhm" or "yeah", or questions, just like you would in real life. 

Give your main character a secret: you can build dynamic three-dimensionality by having your character withhold a key bit of information from their speech. 

Use a layperson character to clarify technical language: The expert character can speak at a technical level, and the uninformed one can stop them, asking questions for clarification.