“Other stylists won’t do it the way you want, so you have to negotiate with them over what you can and can’t have,” Ms. Vanova said. “They create a list of services, and people can either get them or nothing at all.”

After years of training, Ms. Vanova started the Barberette concept in London in 2012 at a local salon before opening her own shop a year later. Her catalog of hairstyles, including Afros and undercuts along with more classically Western fades, lines and partings, was designed for a generation of expressive Britons who refuse to be groomed in a binary fashion.

“They said women don’t belong in the barbershop, but within three years it all changed and I was a part of that change because we were pushing the limits and people liked it,” Ms. Vanova said, adding that she would have up to 40 clients a week.