Lay the ring flat on your work surface. For each plastic-foam ball, push a toothpick partway into it and push the opposite end of the toothpick into the plastic-foam ring.
Cover the front and edges of the ring with the plastic-foam balls, randomly placing the three sizes. Make sure the wreath lies flat on your work surface as you add foam balls so that the finished wreath will hang flat against a wall or door.
Before you spray the wreath with artificial snow, cover your work space and make sure the work area is well ventilated.
Spray the wreath with several light coats of the snow, letting the spray dry thoroughly after each coat.