The next time you negotiate something, make sure you’ve clearly articulated what you want and need.
Check the other party’s understanding, and ask the person to repeat these items back to you.
If necessary, repeat and clarify your wants and needs, being as specific as possible to remove any remaining ambiguities.
Then do the same in reverse. Say, “Here’s my understanding of what you want and need… Is that correct?”
Repeat the process until both of you are satisfied that ambiguities have been removed and all gaps in understanding are closed.
Excerpt from The Transformative Negotiator: Changing How We Come to Agreement from the Inside Out. Unhooked Books