When little girls spend their math classes daydreaming of weddings (instead of winning the World Series -- not to say you can't do both), what do they dream of first? The perfect wedding dress, of course: a gown in white satin with a bustle and sweeping train, the perfect embellishments, and the perfect shoes.

There are few occasions in our modern world where a woman finds herself in a position to wear a no-holds-barred ball gown, much less a crystal tiara, and all too many where she's called on to wear to a neutral suit or uninspiring "biz-caz" combo. No wonder that with so many brides, their wedding plans start with the dress.

Many of these brides are lucky. They may search high and low, braving chilly department stores and pushy bridal shops, but eventually they come face-to-face with The One. They know this is The One because they start crying, or their mother or friends all start crying at once. Suddenly the rest of the planning ... the theme, the tone, the right kind of venues ... it all springs to life.

Other brides aren't as fortunate. They've searched just as hard, working their way through shops across three or four states, but they haven't found The One. Instead, they've found three or four Contenders, all of which are serviceable and nice, but not earth-shattering enough to tell them that now is definitely time to stop the searching and get on with the planning. These brides have it harder.

Even if you're the first kind of bride, buying the dress is such a momentous decision that you run a risk of falling into that wallet-skinning category known as the Two-Dress Bride. Here are some tips for picking the perfect dress and avoiding that awful fate.

- Bring the entourage, but don't buy. It's fun and useful to bring your mother, friends or sisters on the dress-shopping expedition. It gives you a buffer against an overbearing sales staff, and it's fun to see if your impressions of perfection are shared by your loved ones, not to mention how they'll love being part of such an important decision. But no matter how enthusiastic everyone gets over a certain dress, don't buy in the heat of the moment. Give yourself time to reconsider and buy with a cool head later, alone. The vast majority of dresses are non-returnable, so when you've bought it, you've bought it.

- Don't buy too early unless you must. Bridal gowns can take four to ten months to come from the manufacturer, but there's no reason to buy over a year ahead of time, unless your chosen style is going to be discontinued. Give yourself some time to sit on your decision. Once you pick a gown, you'll see a hundred others nearly like it. You'll become a walking encyclopedia on that style of gown. All the better if you still have room to choose.

- If you've bought "The One," stop shopping. Any more window-shopping at this point will only lead you down the road toward the dreary land of Two-Dress Brides. What you need to do instead is remember that blissful feeling of having tried on The One. Go get The One out of the closet, put it on and stand in front of the mirror. You'll remember exactly why it's The One.

- If you've bought "The One" and can't stop shopping, get a second opinion. Show your first and second choices to other brides. Be honest -- tell them you've already remortgaged your condo for the first dress, but you think this second dress might be It. They'll be truthful, too -- the first one was better. You'll feel reassured.

- Don't tell yourself "I'll sell the old dress and choose a new one." This old saw of the Two-Dress Bride just won't work. You'll never get more than a fraction of what you paid for your first dress if you bought it new.

- Don't be afraid to aim high -- no matter what your budget. Some brides knew from the start they wanted a designer label, but life just didn't cooperate by making them heiresses. Yet all is not lost if you're willing to shop courageously. At any given moment, a better-heeled bride is selling her once-used St. Pucchi or Ulla-Maija on eBay. She paid thousands upon thousands, but you, smart shopper, will pay half that or less. To take this road, you must shop earlier than other brides so you'll have a choice of gowns. Always pay with a credit card so you'll have recourse if the dress doesn't arrive in acceptable condition, and again, shop early so you can buy another if necessary. Shop courageously, but not recklessly.

- Shop online, but never send a check. Bridal gown businesses sometimes have a way of disappearing overnight. No matter what the proprietor tells you, never make a purchase as large as a wedding gown without the chargeback protection of a credit card. If they say they can't take plastic, move on.

- Don't hold out forever for The One. Some brides never find The One. What they do find is a few dresses they look beautiful in. If you're this bride, try starting your planning from the theme instead of the dress. You'll probably eventually get sick to death of dress shopping. When that happens, "good enough" really will be good enough. Concentrate on other aspects of the wedding that mean a lot to you, like the venue, the food, or the inevitable adoration of your soon-to-be husband.