1) Get closure first, then divorce. Most people don't seem to do this. They do it the other way around and then do all kinds of stupid, emotionally driven, toxic things during the divorce which just amounts to shooting themselves in the foot.
2) Stay focused on your goal. It no longer matters if the other person "understands" you and all that touchy-feely nonsense. That stuff matters if you are staying together, not if you are going your separate ways. So this means do not take any digs whatsoever at them. Bite your tongue. It isn't worth it (and not doing it is worth quite a lot of money as well as other improvements in quality of life -- an ugly divorce can really make life hard for quite a lot of reasons).
3) The seminal moment where we agreed to divorce set the tone for the entire divorce. We were having the same stupid fight for about the 200th time (actual estimation, not hyperbole) and I stopped screaming at him and quietly said "I don't want to do this anymore. I'm tired of hurting you. I'm tired of being hurt. I think we have both given it our best. If we could do this dance, we would have figured it out by now (we had been married ~17 years). I want a divorce." He was relieved and agreed, something he had not done on any of the occasions where I screamed and cried and shouted "I want a divorce!", which he had accurately interpreted roughly to mean "God, quit hurting me so much". So we agreed to divorce as the only kind thing left to do for each other -- set each other free -- rather than as a means to reject the other person. This means we both worked cooperatively to try to minimize financial damage and the like. If we wanted to make each other miserable, we could have stayed together. We were both very talented at making each other miserable.
4) I also had a class at some point on "Negotiation and conflict management". Getting to Yes and The heart and mind of the negotiator (or mind and heart -- never can keep that straight) were required texts. The first one is short, the second one a lot meatier.
5) Read up on the concept of "prisoner's dilemma" and realize that unlike actual prisoners, you aren't forbidden from talking to each other -- unless you lawyer up and have some lawyer whispering evil things in your ear about covering your ass and telling you to keep your mouth shut.
6) Realize this won't likely work in a genuinely abusive situation. My marriage was tragic, not abusive. Sometimes, covering your ass is the best thing to do.
