NEW YORK — Have the kids had enough fun in the sun and water yet? Let them discover another pleasure of childhood: the dress-up trunk.

Little princesses, karate kids and firefighters can spend hours getting ready and then hours more stretching their imaginations building an imaginary world that happens to fit in your living room.

"Role play, which is what dress-up almost always leads to, is an opportunity to dream, for kids to open their minds," says Jack Ashkenazie, an executive vice president at Almar Sales, which owns My Princess Academy and its line of pettiskirt and tiara sets.

The clothes and accessories, he says, are the tools children use to transform into someone else, even if, in reality, they don't know much about the time, place or duties of that person — and it doesn't matter. Ashkenazie recalls his fantasies of being an army soldier and a ninja, neither of which he had any interest in pursuing as an adult.

Since her daughter is an only child, Cindy Chapman, of Big Lake, Minn., says they rely on dress-up as a primary outlet for play.

The outfits usually lead to homemade forts and tents, or the little girl will end up raiding the kitchen cabinets for a clear bowl for a space helmet or pots and pans for her band, says Chapman, a frequent contributor to Momslikeme.com.

"I never would have thought about the bowls that cost a dime at a garage sale — they're pure entertainment — but a child can," she says.

Just a cape or a mask or an old prom dress can get a child's mind churning, adds Pilar Guzman, editor-in-chief of Cookie magazine. Sometimes the most inspiring bits of a costume come really cheap — like the six-pack of vampire teeth in a dollar store, she says.

And, really, you probably don't even have to leave the house to turn up treasures — old hats and gloves, belts, purses and leftover Halloween gear all take on a life of their own in the hands of a child.

"You don't have to buy all new stuff, you can find great things cleaning the closet," she says.

Dress-up can entertain a group, even a party, adds Jeanne Benedict, a Los Angeles-area party expert for Celebrations.com. She's also the mother of a 5-year-old "glamour girl."

Kids are interested in role-playing from a very young age, Guzman says, and toddlers are probably the sweet spot.

Older children will still play, but might use more real-world items and a little less imagination.

Benedict sees girls, in particular, moving away from dress-up and into makeovers or pretend photo shoots around 8. Still, they're having fun and using many of the same items from the bin.

If you're doing costumes for a crowd, Benedict suggests taking the stuff out ahead of time and setting up a mini department store, with shoes on one table, capes on another and all the hats in yet another spot.

Her other tip: Give out tiaras, wands or swords as party favors. Then there are enough to go around.

DRESS-UP IDEAS

• An oversized T-shirt with a rope belt turns a toddler into Yoda, and a motorcycle helmet doubles as astronaut gear, Guzman says.

• Dad's belt can holster plastic or cardboard swords and sabers.

• Adhesive fingernails and earrings, as well as makeup, are big hits with girls of all ages, Benedict says.

• Stiff foamboards, often found as packing material, can be cut out into a mean guitar, suggests Chapman.

• Shop clearance racks for postseason paraphernalia such as rabbit-ear headbands just after Easter or gardening gloves at the end of summer.

• Consider the "twirl factor," says Ashkenazie. Sparkle, glitz, pink and purple — "anything that has a strong fantasy look — are his brand's top sellers among 3- to 7-year-old wannabe princesses, he reports.

•"Boas! Everyone loves boas!" according to Benedict.