Flat-heeled shoes have stepped up their game to emerge as a hot fashion trend for the spring-summer season.

The detailed and embellished ballet flats, sandals and peep-toes have been elevated to become a serious alternative to the high heels that some women still feel are needed for dressy or business occasions.

In fact, the flat-shoe shape might be a better complement to this year's longer, more languid fashion silhouette.

"Flats are one of the cool ways to wear spring outfits," says Paola Venturi, creative director of Via Spiga. "I like to see a bronze-colored T-strap in a bronze color with a dress in a bright color — maybe a carrot or tomato red — and I love a graphic-print, black-and-white dress with a granite version. For the '70s influence that's everywhere, I think a thong is really sophisticated."

She sees a peasant blouse, wide-leg trousers and thong with rhinestones, influenced by vintage belts she found in an Italian marketplace, in her future. The jewel details "makes it feel like a city shoe," Venturi explains. "It's not a casual pair of flip-flops."

With longer hemlines — and especially the tricky mid-calf pencil skirt — higher heels can throw off proportions, says Lauren Dupont, creative director at Jack Rogers, a brand best known for its thick, leather stitching, popularized by Jackie Kennedy.

The shorter shoe "grounds" the outfit, Dupont explains. The shoe doesn't have to be completely, perfectly flat, but a shoe with just a bit of heel creates an easy line from the leg, she says, and, if there's an ankle strap, you've just ramped up the sex appeal.

Choosing a black heel or sole instead of, say, a more casual natural wood color adds refinement.

Even Jimmy Choo, a brand synonymous with strappy stilettos, has several flat options, including a zip-back sandal "perfect for lazy days spent poolside," according to its website, and a glamorous, beaded tribal-style option.

While company co-founder Tamara Mellon is always photographed in heels, flats are an equal partner in her wardrobe. That's what she wears for the "every days," when she's going to the office or on an errand with her daughter.

The flat shoe is a safer place to introduce some of the bold, bright colors that are another must-have for spring. Just a swath of yellow, blue or violet across the band of a sandal is an easier adjustment for the eye than four inches of that color on a heel.