The moment you and your friends descend into the London cocktail lounge known as BYOC, you’ll notice something missing: the alcohol. You knew that when you booked your reservation, and were savvy enough to pick up a couple choice bottles before heading out. After all, BYOC stands for build-your-own-cocktail, and you just need to bring your favorite base spirit to start having fun. After paying the 20 pound cover, head down the juice shop-adjacent staircase and grab one of the wooden booths in the cozy, brick-lined bar. Within moments, your personal cocktail attendant will arrive with a trolley packed with bitters, herbs, juices, syrups, and fruit, so hand over your side of the equation and watch the magic happen. There’s no menu, so just tell your mixologist what kind of flavors you like and they’ll make you a round of bespoke drinks on the spot. And don’t worry about bringing a bar’s worth of liquor to cover your cocktail bases. The bartender can broker an exchange between tables, mix your champagne with someone else’s gin, toss a little of his own fresh lemon juice and simple syrup in, and, just like that, you’re passing French 75s around and making toasts to friends you just met. With each drink a custom creation and each visit a new experience, the only solid expectation at BYOC is a great time.