Seconds after we meet over a video call, Cliff Tan has diagnosed my living room: The space is in desperate need of a roller blind. “It will filter the light, give you some privacy and remove all that cutting energy,” says the 35-year-old architect and TikTok phenomenon. He explains that the stripy shadows from the wooden slats over the window create tension, “like in the interrogation room in the movies.”

With humor and candor, Tan uses the teachings of feng shui to give his two and a half million followers practical advice for transforming their living spaces. The ancient Chinese art form applies a range of concepts to optimize energy flow and create balance between important elements in rooms and buildings. “Feng shui is about finding the best place to be,” he explains. �...