When topped with shimmering votive candles, a mirror becomes a pool of reflective light that casts a glow onto the reception tables. For this centerpiece, we stacked a 14-inch-diameter mirror on foam boards to make a platform, then covered the edges with a wide ribbon and added a thinner ribbon for decoration, folding ribbon ends under and securing them with decorative-head pins. To decorate the vase, we wrapped a coordinating ribbon around the bottom and fastened it in place with double-sided tape; it's best to use a tall vase like this cylinder so the blooms won't get close to the flames even if they droop. Because the ribbon we chose was 1-inch wide, we combined our 1/4-inch-thick mirror with 1/2- and 1/4-inch-thick foam boards (cut to match the shape of the mirror with a utility knife) to create a 1-inch platform; once you've selected ribbon, you can use as many layers of foam board as you need to get the proper height. The ribbon we used for accent is 1/3-inch wide.
Read more at Marthastewartweddings.com: Mirror Centerpiece