Try: Air-dried hair.

Before Proenza Schouler’s show, damp-haired models could be found lining the sunny Chelsea, N.Y., sidewalks outside the venue. It was all part of the prep for Anthony Turner, lead stylist for Bumble and Bumble. “We’re celebrating each girl for exactly who she is—all the little mistakes that happen in their hair,” he said. “To achieve that, we shampoo and send the models outside to air-dry.” To prevent frizz, Turner applied Bumble and Bumble Hairdresser’s Invisible Oil ($50) but steered clear of the roots so that the hair would “feel light and move on the runway.”

Not every woman’s natural hair texture requires, or allows for, a wash-and-go style. For hair that had relaxer growing out, Turner used a small curling iron to create consistency. A rich mask like Kérastase Chronologiste Crème de Regeneration ($72)...