KATIE SLONIM spends her days as a nanny and her nights hosting private mixology group lessons for her cocktail startup, Mixo, an idea that took shape as she was searching for something to do during a friend’s bachelorette party. “Hey, I’m an amateur, so you can do this, too,” says Slonim, who learned much of what she knows about the craft from YouTube tutorials. She turned her cocktail-making interest into a business in June, charging $50 a head for her two-hour classes that she schedules through her Instagram page (@mixoindy). Because the details are important to her, Slonim arrives an hour early to set up wooden cutting boards, linen napkins, tools, and nice glassware for the guests, who will learn how to make two cocktails from scratch. But her true goal is to get her clients as excited about the craft as she is, and that is usually an easy sell. “It’s the tactile nature and the ritual of making a cocktail that keeps you coming back to the art of mixology,” Slonim says.