Simple wedding centerpieces like these are made in a trough container (that means long and rectangular). You need to be sure to choose one with a liner so it doesn't leak out on your wedding tables.
You will need:
Float soak the florist foam in water treated with Crystal Clear Flower Food. Insert the flowers into the foam in random pattern. Mist well with Finishing Touch or Crowning Glory and keep either refrigerated or in a cool darkened room.
Design rings also come in 10.5" as well. For more detailed help on creating table wreaths, check out the step by step tutorials on the Table Wreath Gallery.