Invent Options for Mutual Gain
You can’t settle on a good outcome without having the right ideas. Separate your brainstorming from the decision process. Ban judgment and throw out the craziest ideas you can. Then use those ideas as launchpads for refinement.
Try to understand why everyone came up with different ideas. Use these differences in values, believes, and interests to settle on an outcome. You can’t reach an agreement without differences. Ebay wouldn’t exist if everyone thought their old junk was worth the same amount. The only reason Ebay works is because people have different values.
Finally use all this information to make the decision easy. There is value for sides in every negotiation. Don’t make the situation worse than where you started. And Give them a choice they can just say yes to.
Book: Getting to Yes