I dislike infantile beauty products. Not literally (baby soap is bomb), but I avoid anything that skews my appearance toward childishness. The verboten: headbands (unless turbaned and vaguely reminiscent of Bianca Jagger), bows, scrunchies, Matryoshka doll-like blush, and (except on those rare occasions I wish to emulate a J.Crew model) garishly pink lipstick. The only thing I didn't include on that list is barrettes, but this is a recent development.

“Good for her! Not for me,” Amy Poehler says in her book Yes Please, which sums up my thoughts about hair accessories aside from a simple, black elastic and, now, the barrette. What gives? The brand that could make fur slippers, if not literally cool, enormously covetable: Céline. At their Spring 2015 show, a golden, circular barrette fastened models' half-up, half-down hair.

Then, Trace appeared in a meeting with an oversized barrette, holding one-side of her lob. Another friend met me for coffee with her hair tucked into a tortoise clip. Clearly, a trend was sensed, and I took to a little online shopping to scope out further options. Quietly elegant, sparse stores like La Garçonne, Creatures of Comfort, and LISA SAYS GAH stock streamline, metal barrettes by French designer Sylvain Le Hen. And the epitome of youthful maturity, Sophie Buhai, offers two sculptural hair slides.

A pragmatic and democratic device, the barrette works on all hair: short, medium, long, hair that's air-dried and free of product, hair that's been mussed-up with a texturizer of choice. It works on unwashed and slightly greasy hair, smoothed-back by way of water or gel—the possibilities are endless. Its ease is its appeal, so avoid hair spray.

The ideal barrette will be:

Made of: sleek metal or smooth tortoise

Shaped: long, always geometric, perhaps overly chunky or whisper thin

Sized: undoubtedly large enough to contain all of your hair

Unadorned: avoids rhinestones, insects, and any embellishments that may snag a silky work shirt

C.O. Bigelow carries the perfect barrette from Charles J. Wahba that's aesthetically adult enough for “real life.” And at $12, it's still within the confines of one’s childhood allowance.

—Alexis Cheung

Image via Getty. Also childlike, but can be turned incredibly cool? Flowers in your hair. No trip to San Francisco required.