For anyone who harbours ambitions of ever leaving the house without, say, birds’ nest hair and half their breakfast smeared across their faces, then a good mirror is, of course, a necessity. But beyond this practical function, the best ones also have the power to bring light, depth, and a sense of drama to interiors. Whether sleek and contemporary or steeped in antique charm, a beautiful mirror can completely transform a space, making it seem bigger and more expansive. We go through the looking glass to pick the fairest of them all, from the decorative to the understated.