Being great at negotiation has enormous payoff. From negotiating a raise to buying a car, you can apply the Harvard principles of negotiation to maximize value in your everyday life and work. 

Separate the person from the issue.

Don't let the quality of your relationship with the person interfere with your interest in the issue. Negotiate hard but don't be hard or unfriendly on the person. It is in your best interest to understand the interest of the other person. The other person is your partner and not your enemy because if you could order what you want you wouldn't negotiate.  

Negotiate not based on position, but on interests.

While creating a solution for the issue at hand, examine the interests of the people around the issue and negotiate based on the interests of the parties involved and not on the positions they hold. 

Develop criteria that a solution must fulfill.

Develop a set of criteria you require in the final outcome that would get you to say "Yes". Then fully understand the criteria the other party requires. Lead with this collective information to find an option that would fulfill the criteria of both parties to create a win-win solution. 

Develop several options to choose from.

People like to choose. Instead of proposing one best solution, offer options to the other party based on their criteria. By doing so, the other party gets an opportunity to evaluate, and the negotiation would be much more sustainable because they get a sense that they had a choice.

Use these principles next time you want to foster cooperation and avoid competition.