1. Never present your bottom line early in the negotiation. In a negotiation you always want to leave room for bargaining and compromise.
2. Argue issues, not positions. For example, you and your spouse are discussing who pays for the children's college. Your spouse says the kids will go to state schools; you say they're going to the best school they get into. The two of you are arguing positions, not issues. The issue is the cost of college and how you'll finance it.
3. Make ground rules for your discussions in advance. If you and your spouse are meeting alone, write out a schedule of topics to be covered and stick to it. Agree that neither of you will interrupt the other.
Tone and Manner are Key!
4. Be flexible. That doesn't mean cave, but be ready to compromise. Referring back to the college tuition example, suppose you don't want to pay anything for college, and your spouse wants you to pay half. What about paying one-third? What about each of you paying based on the percentage of your combined financial statements at the time the children go to school so long as you both stipulate that you both pursue scholarships or school loans?
5. Be ready to trade. Say that you want the gold necklace that your husband bought you on your third wedding anniversary and he really wants the cookware. You want the cookware, too. Decide which one you want most, and if the values are close enough make the trade.
6. Leave heated issues for last. This is a lawyer's trick. Resolve everything you can and save heated issues for last. Maybe you both want sole custody, and the issue of shared or joint custody isn't even on the table. If you start off discussing sore points, you'll get nowhere.