Don’t try to force your opponent to admit that you are right. Aggressive confrontation is the enemy of constructive negotiation.
Avoid questions that can be answered with “Yes” or tiny pieces of information. These require little thought and inspire the human need for reciprocity; you will be expected to give something back.
Ask calibrated questions that start with the words “How” or “What.” By implicitly asking the other party for help, these questions will give your counterpart an illusion of control and will inspire them to speak at length, revealing important information.
Don’t ask questions that start with “Why” unless you want your counterpart to defend a goal that serves you. “Why” is always an accusation, in any language.
Calibrate your questions to point your counterpart toward solving your problem. This will encourage them to expend their energy on devising a solution.
Bite your tongue. When you’re attacked in a negotiation, pause and avoid angry emotional reactions. Instead, ask your counterpart a calibrated question.
There is always a team on the other side. If you are not influencing those behind the table, you are vulnerable.
Never Split the Difference: Negotiating As If Your Life Depended On It
Voss, Chris; Raz, Tahl.