Sand Ceremonies are ideal in outdoor settings where wind may be a factor. It creates a beautiful visual effect for memorable photographs as well as the commemorative keepsake you take home with you. If you'd like to honor both mother of the bride and mother of the groom, you can have them walk down the aisle before the ceremony with a small vessel of sand to place beside a larger empty vessel for the ceremony. You may also wish to coordinate the color of sand with your wedding colors. Or think of a room in your house you will wish to display your unity sand sculpture in and then coordinate with the style and decor of that room.
I like the example displayed here. This couple chose to fill an hour glass to signify the beginning of a new time in both their lives. Long after their wedding day is over, the hourglass remains in their home office as a discreet keepsake.