In their book “Getting to Yes”, Roger Fisher and William Ury develop four principles of negotiation, which can be used effectively on almost any type of dispute.

The four principles are:

1) separate the people from the problem;
2) focus on interests rather than positions;
3) generate a variety of options before settling on an agreement;
4) insist that the agreement be based on objective criteria.

Read more on http://www.negotiations.com/book-reviews/getting-to-yes/ or http://www.colorado.edu/conflict/peace/example/fish7513.htm