All that is required is a willingness to look for a fair way to settle the issues that must be decided. You don’t have to be best friends to mediate. Many people find that mediation helps them to communicate better, especially if there are children involved.
Even if you depart as “best enemies”, through mediation you will have had the opportunity to have your needs and wants discussed, and to reach an agreement that you both can live with in the next phase of your life.
Because you’re paying one mediator instead of two attorneys and because you are doing the negotiating and not your lawyers, the cost of mediation is less then half of a traditionally litigated divorce.