Arouse in the other person an eager want -- One of the Fundamental Principles in Dale Carnegie's How to Win Friends and Influence People.
I had a very quick negotiation with my Wife's 11-year-old brother a few days ago. She was watching him and wanted him to take out the trash; he wanted to play video-games. I was getting angry because I didn't like seeing my wife disrespected by this person she was helping out.
And then it hit me that he was desperately waiting for something to be delivered to him in the mail. Most of his battle was putting down the game-controller, so when I said, "I'm surprised you're not running outside to the mailbox, because it was delivered about 30 minutes ago," he immediately started to head for the door. Taking the trash out wasn't as big a deal when he was already up and moving around.
Everyone was served because interests were sought instead of hard stances on positions.
Arouse an eager want: Instead of forcing my will on Sam, I was able to see a connection to something he wanted. Dale Carnegie's suggestion eliminated hurt and angered feelings by seeking a new way to get things accomplished.
Often the advice given in books such as "How to Win Friends and Influence People" and "Getting to Yes" is difficult to follow because you do get emotionally locked into your position and the righteousness of that position. I was quickly moving from "wanting my wife to not have to deal with disobedience" to an attitude of anger and a desire to force this kid to obey everything I said because I said it.
We have to give up those immediate emotions of satisfying ego, pride, anger, or revenge and actually get the deal we'll be happy with a few days later.
Talk about Interests: This is one of the ideas in "Getting to Yes." It was quick, but when I spoke in a friendly manner about his real desire being outside it was very easy to tack on an additional task. When speaking to Sam's interest, the pie was expanded and he excitedly carried out his task.