Entranced by true love's dazzling combination of hormones and ignorance, we may commit to sharing a home with our beloved before we've thought through the consequences. If you're considering moving in together, you may want to push your imagination some distance beyond the usual happily ever after. Love can conquer many a romantic hiccup that arises after a move-in, but only if you take a few key precautions. Step 1: Pledge allegiance to red flags No, I'm not suggesting you turn communist. By red flags I mean the uneasy feeling that there's something fundamentally wrong with your relationship. I know several clients who've moved in with partners in order to silence just such hunches. Two, ten, 30 years later, as I'm helping them process the inevitable breakup, I ask, "When did you see the problems?" Almost invariably, they respond, "On our second date" or "The week we met" or some other astonishingly early moment in their relationship. Research suggests that we can sense red flags in someone else's marriage after watching a troubled couple interact for just a few minutes. Turning this intuition to ourselves, we can scout for scarlet banners in our love lives -- before, not after, moving in together. Pay particular attention to what psychologist John Gottman calls the Four Horsemen of relationship apocalypse: withdrawal, criticism, defensiveness, and, above all, contempt. If these elements characterize your relationship, you might want to hang on to that loft-for-one. Thinking you can solve basic interpersonal problems by moving in together is like trying to transform a rabid pit bull into a love pup by stapling its tail to the parlor floor. You'll still have a big angry mess on your hands -- only now you'll be living with it. Step 2: Articulate your assumptions Most of us outgrow such prejudices as we gain experience, but even tolerant people retain a surprising number of untested assumptions shaped by life experience. All couples have slight-to-serious differences in their beliefs about what is "normal." From doing laundry to dealing with stress, we tend to think that our way is the way. It isn't possible to resolve all these clashing assumptions (or even anticipate them) before shacking up. But you and your mate can discuss the fact that undiscovered prejudices will emerge, and have a system in place for dealing with them. Agree to discuss at least four options whenever styles conflict: my way, your way, our way, or both ways. For instance, suppose your impoverished childhood taught you to reuse aluminum foil, while your mate's family just threw it away. If you and your partner are pinching pennies, you may decide that reusing is a fabulous idea (your way). If you become prosperous, you may decide to pitch your used foil (his way). If this feels wasteful, you could adopt a new custom by recycling (our way). Or you can simply agree to disagree, giving him permission to toss used bits of foil while you treasure them like the Dead Sea Scrolls (both ways). If you decide to adopt a practice that is different from your past experience, remember that it takes about 21 days of performing a new behavior before it becomes a habit. You or your mate may feel grumpy during this time, but by sticking to your agreement, you'll find things should smooth out in three weeks or so. Step 3: Decide who wears which pants when Among the myriad assumptions that make cohabiting problematic, there's a category so confusing and volatile that it deserves special attention. I'm talking about gender roles, the expectations about the respective responsibilities of each partner in any given relationship. In our culture, traditional divisions between "what men should do" and "what women should do" have been destabilized by massive ideological and economic trends, creating domestic conflicts in the process. These days there's no rule book for divvying up labor at work and at home. Modern women, as well as men, may wear the pants in the family -- but no one's really sure who wears which pants when. Unless your assumptions are a perfect match for your partner's (not likely), they can create serious rifts when you begin living together. You and your partner need to talk about the division of labor in your prospective household. Domestic and professional responsibilities often conflict, which means you both might be overburdened. Can you decide now who wears the required pants for virtually every task involved in managing your household: cooking, cleaning, calling the plumber, working overtime to pay for a new fridge? Figuring out who tackles which role may take a lot of start-up time, but believe me, it can save you enormous long-term conflict. To do it right, though, you'll need some training in negotiation. Step 4: Negotiate needs, not positions In the rosy glow of fairy-tale romance, it seems impossible that you and your true love will ever have serious differences. Moving in together will dissolve that little illusion as fast as you can say "What the hell are you doing with my CD collection?" You can avoid ruining a relationship if you have one negotiation skill: addressing needs rather than positions. This simple strategy has helped many of my clients smooth out relationship wrinkles. For example, Scott loved to eat out; his girlfriend, Peggy, always wanted to stay home. They argued a lot about this issue. I asked Scott why he wanted to go out. "I like ethnic food," he said. Peggy's concern was that they couldn't afford restaurant meals. Once they identified their objectives, it took Peggy and Scott only minutes to dream up a weekly date, when they'd pick a menu from an ethnic cookbook, then shop, cook, and eat together. Working from why -- rather than repeating what you want -- is one of the quickest ways I know to short-circuit arguments like this. Step 5: Avoid tunnel (of love) vision It takes time and effort to establish a workable live-in love. But don't let the exciting, tumultuous process of setting up a house distract you from your nonromantic relationships. Couples who focus too completely on each other may become enmeshed, develop what I've taken to calling tunnel-of-love vision, and abandon friends, family, and private time. No matter how engrossing your new living situation may be, this is a bad idea. Sustaining a happy domestic life requires a resilient support system. And maintaining that network is imperative, by either spending a few minutes every day in peaceful solitude or having coffee with friends. You'll be in a much better position to handle a career crisis, the death of your goldfish, or a near-lethal PMS attack without stressing your new roomie beyond all human endurance. It's true that territory beyond moving in together, beyond The End, is less like a fairy tale than early courtship. The sequel tends to sound less exciting and more mundane, its themes increasingly subtle and complex. It requires attention to our intuition, careful expression of confusing emotions, skillful communication, and a good deal of consistent daily work. The story of a contented life together is frankly less fun to tell than the uncertain adventure of finding love. On the other hand, it's much more fun to live.