The rule of three in home decor means arranging objects or elements in groups of three to create balance, rhythm, and visual interest in any room. For example, a trio of vases with varying heights, or three framed prints above a sofa, naturally attract the eye and feel curated without being stiff. This approach helps style faster by organizing what you see in a way the brain loves, creating a calm, layered, and alive space. To start, focus on grouping items in threes on mantels, shelves, and coffee tables for an effortless and intentional look.