People can prepare themselves before a divorce by having enough money saved for their attorney and some living expenses.
Suppose you and your spouse have been covering everything jointly, but now you’re going to have to do it yourself. In that case, you should have savings for a security deposit on a new apartment or a down payment on a new house. Or, if you’re going to keep the house instead of paying the mortgage fifty-fifty, you might suddenly have to pay it yourself.
You want to be financially ready for those things. Other things you can do is to have important papers either stored somewhere out of the house or copied. You never know when you might need birth certificates, social security cards, or your marriage certificate.