If your goal is to avoid a court battle and the high costs that go with it, then you want to avoid any accusations of personality flaws. Be aware of your spouse's sensitivities and avoid inflaming them. Compromise is the essence of divorce negotiations, and if you say and do things to encourage your spouse to dig in and be inflexible, you're asking for a war.
No matter how much you despise your spouse; no matter how many ways you feel you've been wronged, don't make a bad situation worse by identifying your spouse's vulnerabilities when trying to reach a settlement. Always try to negotiate before you litigate.
Lawyers can turn good divorces into bad ones and bad divorces into nightmares. It's not just divorcing spouses that are difficult. Certain lawyers are intent on churning fees, and they can cleverly manipulate situations to their financial advantage. The result is couples who will fight over the big and little things and invariably wind up in court and broke. Do not fall for the myth that you have to find a take-no-prisoners attorney, someone who is ruthless and will use any tactic necessary to "win" the case. When there is one difficult attorney, the odds are the divorce will be costly and unpleasant. When there are two difficult attorneys, the divorce will be a total nightmare.
The last thing you want to do when your spouse announces she wants a divorce is to become completely acquiescent. Many people are manipulative, and if they think they can manipulate you into getting what they want out of the divorce, such as money, property or custody, they will do so. If you are stunned or saddened, you may agree to anything and everything your spouse recommends. Don't confuse passivity with being reasonable. My experience is that the shock of divorce soon wears off, and once it does, you're much less vulnerable to making this mistake.