If you want to deescalate a conversation then you must be aware of what you are saying, combined with your body language.
In a tense conflict, you need to know what helps you and what likely would escalate the situation:
Don’t challenge your opponent.
Don’t give orders
Don’t insinuate that he/she is wrong
The remember-code in Danish: UTOPI
This should be practiced; it is harder than it looks like in writing. For example, the sentence “take it easy” is an order to your opponent, and an insinuation telling that he/she is wrong.
This is not a law or a true rule, sometimes the situations dictates that an order acutely helps, it might “shock” your opponent if you answer: “don’t fuck with me”, but in most cases this will escalate the conflict.
When you go into a dialog whit the intent to diffuse, you should listen. What is this person saying? And then you must reply. Sometimes in a conflict you have a choice that is given to you. “get out or I will smack you”. Well you can try to get in a dialog because you maybe have the right to be there, or you can choose to walk.
Sometimes when you are in a conflict it is just a good guy that’s having a bad day.
This is a situation you should be able to diffuse using empathy and verbal
Other times it’s a bad guy on his normal day. This is harder to diffuse and you must be ready to fight.