02/21/2012 07:10 am ET Updated Apr 22, 2012

5 Mistakes Stepfamilies Make

There's something hilarious about the phrase "blended family." As though you can throw two sets of hostile people in the blender and serve them poolside with fruit kebabs and little paper umbrellas.

I'm something of a maven on this subject, having had two stepfathers, two stepmothers, three step siblings, and one stepchild over the past 40-odd years. I've seen at least six therapists specializing in blended family dynamics, and dealt with two generations of baffled but well-meaning neighbors and friends.

Based on my uncertified experience, here are five common mistakes and one piece of time-tested, worthwhile advice.

Mistake 1: Assuming the rules are the same. It may seem blatantly obvious to you that Ho-Hos aren't allowed in the house, that four-year-olds shouldn't play Call of Duty and that parents are allowed to sleep until 10 on Sunday mornings. Guess what? Not only isn't it obvious to your new family, they aren't going to see the wisdom -- or the logic -- of your rules.

Mistake 2: Expecting your spouse to back you up. Yes, mom and (step) dad are supposed to present a united front. But when you ask your partner to support a change in parenting style, you're implicitly criticizing everything they've done up until now. Chances are, there's going to be pushback -- passive or aggressive, depending on their personality type. Try not to take it personally.

Mistake 3: Drawing lines in the sand. Short of infanticide, there are very few unbreakable rules in a stepfamily. Everyone's trying to navigate this unfathomably difficult situation as best they can; do you really want to throw all that work down the toilet because a five-year-old hid her stepbrother's stuffed bunny?

Mistake 4: Expecting other family members to give 50-50. I can't think of any place where quid pro quo is less feasible than in a stepfamily. Here's the unvarnished truth: You'll need to give 100 percent, pretty much all the time, and so will your partner. That's why weekly date nights and periodic couples' getaways are so important. You need a place to recharge.

Mistake 5: Getting hung up on appearances. What makes a successful family? Roseanne Barr said, "If the kids are alive at the end of the day, I've done my job." A good family provides a safe environment that encourages the healthy development of its members. Whether that looks like Ozzie and Harriet or Malcolm in the Middle is nobody's business but yours.

Finally, here is the one piece of advice that I have found indispensable in creating successful step-relationships: Let time pass. Just as you can't make a plant grow by pulling on the leaves, you can't make a family come together through desire or will.

Be patient with one another. Celebrate your successes (however small). Lower your expectations and then lower them again. One day, you'll look around and realize that this strange, prickly group of ridiculously difficult people has got your back. And that you've come to love -- or at least appreciate -- every one of them.