Actually, design principle #3 is the number 3. There’s just something about 3. Things in threes are simply more appealing. Five, seven and nine, work just as well as, too, However, three holds the magic. When viewing things arranged in odd numbers, your eye if forced to move. This movement creates for a more visually interesting experience.
If you have an area that is difficult to fill, try using a grouping of three different furnishings to fill the space. Vary the height, width or depth. The trusty triptych can fill a large wall. Use colors and textures in threes when considering accessories. When it comes to shelving, the principle works there as well. Try grouping vases or bowls in odd numbers there, too.
Instantly bump up your room’s Wow Factor by experimenting with odd numbered grouping, particularly the number 3. You’ll never have a dull, boring room, again.