Safeguard heirlooms and liquid assets. Seek appraisals for artwork, antiques, and other collectibles. Take any sentimental or important objects to a friend's house for safekeeping. Be certain that your name is recorded on the house deed or apartment lease. Do not stash cash in a safe deposit box; for pending litigation, boxes are sometimes sealed. Make sure you revoke any powers of attorney your spouse may have and ask brokerage firms to check for identification before your name is signed to anything.
Open a bank account in your name. It only takes one party to raid an account, and you don't want to be left without any money. Certainly do not deposit any more of your own money into a joint account, even if you transfer that into your own name. Establish a new account for future deposits, preferably at another bank. This is where you can keep an emergency fund to live on and pay legal bills, at least until support is established. Don't be surprised if a spouse petitions for joint accounts to be frozen, pending equitable distribution in a divorce. This is another reason to have your own access to funds.
Establish credit in your own name. As soon as separation takes place, cancel or report missing jointly held credit cards. Then, go out and set up new accounts in your name only.
Pay as many bills as possible. Do this prior to separation so that you are not stuck with the obligations, risk having utilities shut off, or fight off a bad credit rap.