A mirror is one of the few decorating tools that actually does something beyond looking nice. Hung well, it pushes light deeper into a room, doubles a good view, and makes a small space read bigger than it is. Hung badly, it reflects a blank wall, a heap of mail, or a ceiling light glaring straight back at you. The whole difference comes down to placement, and the rules are simpler than you would think once you start paying attention to what the mirror is actually pointed at.
Put Mirrors Where They Reflect Light, Not Clutter
Before anything else, ask what the mirror will reflect. Hang one across from a window and it catches the daylight and throws it back into the room, which is why this single move can transform a dark space. Hang it where it catches a lamp and it does the same job after dark. Hang it facing a blank wall or the underside of a shelf and it does nothing at all. So stand where you normally stand, hold the mirror up, and look. If what you see is something you would like more of, you have found the spot.
Size It to the Wall, Not the Furniture
Mirrors are one of the few things worth sizing up past the point that feels safe. A little mirror on a big wall looks stranded. A generous one, whether a single piece or a cluster of smaller ones, holds the wall and gives back more of the room. Over a console or a fireplace, aim for something that spans roughly two thirds to three quarters of the furniture below it. And a full-length mirror leaned against the wall makes a room feel taller while doubling as the thing you actually check your outfit in.
Use Them to Solve Specific Problems
The same mirror solves different problems depending on where it goes. A narrow hallway feels wider with one running along a long wall. A dim entryway feels warmer with one facing the door. A tight dining corner opens up with a large mirror bouncing back the table and whatever light is in the room. Work out what the space is missing first, whether that is width, light, or depth, and let that decide the wall.
Avoid the Common Mistakes
A few things to avoid. Do not put a mirror where it reflects something awkward, like straight into a bathroom or across the top of a staircase, where it can be disorienting rather than pretty. Do not hang it so high it shows the ceiling instead of the room and the people in it; eye level for someone standing is the safe default. Do not expect tiny decorative mirrors to move light or space around, because they are ornaments, not tools. And think twice about two mirrors facing each other, which gives you an unsettling endless tunnel instead of the open feeling you were after.
