We all want an appropriate degree of autonomy. When someone impinges upon it—whether intentionally or not—we tend to experience negative emotions. When it is respected, we tend to feel engaged. As you negotiate, take the initiative:
Expand your autonomy. Whatever your authority, you can always make a recommendation or suggest inventing options before deciding. Joint brainstorming is a practical process for you to invent options for mutual benefit.
Avoid impinging on the other person’s autonomy. You can consult before deciding, whether with a colleague or with invisible stakeholders. By respecting people’s core concern for autonomy, you can stimulate positive emotions in them and in yourself.