Negotiation is a way of life.
We all have to convince other people of certain things, we might be a mother trying to teach our children to behave properly, or a high level executive trying to turn our team into leaders.
I have found that the best way to negotiate for long-term success is focusing on what the other person wants, and making sure that they leave the negotiation feeling awesome, like they received not only what they wanted, but perhaps even more.
Of course, doing this while not getting royally fucked over is an incredible skill. It requires the expert navigation of what I call negotiation line items. It means always asking for something in return, no matter how trivial, and having a crystal clear goal in mind.
The final requirement is that you also have a line in the sand, things that you simply cannot compromise on, and that you make the reasons behind your logic understandable to the other party.