Don’t give the bad guy a gun—know what’s negotiable and what’s not negotiable before you start.
Conduct intelligence gathering before starting to negotiate. Continue gathering intelligence as you negotiate.
The first goal of the negotiator once negotiations start is to establish rapport.
There are no quick fixes in negotiations—don’t trust one even if it looks like a gimme.
The best way to build rapport with someone is by showing them respect. Don’t bully them, don’t look down on them.