Active Listening: Just defending your proposal puts you at odds with your counterpart. Listening "without judging" and ensuring the other knows you're doing so lets you understand their value system and then adapt your proposal to fit it.
Empathy: Understand why the other feels a certain way and then connect by sharing those feelings.
Rapport: After empathizing, respond with words that will resonate with the person you are negotiating with.
Influence: After showing an understanding and willingness to help them achieve their objective. Now, you have leverage to problem solve with and help them reframe their objectives.
Behavioral Change: Finally, you propose alternatives that stand a chance to achieve an acceptable outcome.