Be a Mirror
I’m nearing the end of reading Never Split The Difference by Chris Voss, and reflecting (No pun intended) on some of the key elements of the book.
One of the principle tactics Voss describes from early on is mirroring. In a negotiation, mirroring is the simple act of repeating the last one to three words of what your counterpart has just said.
Doing so will help them feel like you’re really listening to them. It’ll foster a bond between you. It will also prompt them to do more talking or explaining, which can end up making your job easier, as they often times end up negotiating with themselves rather than with you.