DECORATE YOUR MANTEL
Choose treasured items that you want to display, as the fireplace is the natural focal point of the room. The general rule is to choose a tall item for the center of the mantel, and shorter objects on either side.
A simple style that works for both formal and contemporary rooms is to place one large mirror, painting or portrait centered above the mantel, and matching candles (or other tall narrow items) on either end of the mantel shelf.
Another method is to mix and match the items displayed on your mantel. Again, begin with the mirror or artwork centered above the mantel. One one side choose a single tall item such as a vase, candelabra, tall mantel clock, sculpture or other bold piece. On the opposite end of the mantel shelf, choose 3 objects that are roughly half as tall as the single object - yet varying a bit in size and shape - at the first side. These 3 items will ideally create a theme of items or colors (3 framed photos, 3 vases, 3 candles, 3 pewter objects, 3 blue items, etc.)
Ideally you want to end up with an odd number of items displayed on and above your mantel.