Maybe you want to buy a house while interest rates are down, or maybe you already have one and the only thing you need is a vacation. Or you want to be debt-free a year from now, or send your kids to college or go back to school yourself. Work out a game plan together so you know what is coming your way, when, and how you'll foot the bill. Talk about your short-term goals (the vacation) and the long-term ones (retirement), and make sure you share a similar picture of the future. A little foresight goes a long way.
Remember, too, that there are some things—layoffs, major car maintenance, medical bills—that you just can't predict. This is where an emergency fund comes in. Pull at least three to six months' worth of living expenses together so you have it at the ready in either a savings or money market account.