Float some flowers in the pool to decorate an outdoor setting for a wedding or a midsummer's night party. It's fairly simple to assemble a live or artificial flower float -- fake flowers will last longer, but real flowers are fragrant and fragile. Fill the pool with a flotilla of flowers or create a solitary focal point. If you scatter loose blossoms in the pool, remember to turn off the filter pump.
Soak a block of floral foam in water until it's saturated. Cut it in half lengthwise to make two thinner pieces of the same height.
Hot glue a piece of polystyrene foam to the bottom of a tray just large enough to hold the soaked floral foam. Once the tray-float dries, flip the tray to the right side and place the floral foam on top of it.
Clip the stems of real flowers and greenery fairly short and poke them into the floral foam. Keep the arrangement low and centered so it will remain balanced in the pool. Start with the greenery or leaves for background, and then add the blooms to create the design.
Cut artificial flower and greenery stems with a wire cutter if you've opted for a long-lasting or reusable arrangement. Poke the stems in the foam, just as you would for real flowers. The arrangement stays fairly dry, floating over the pool surface, so you may use realistic silk flowers rather than settling for plastic.
Cut a small circle in the floral foam, just large enough to cradle a protective holder for a tea light or candle, before building the flower arrangement if you plan to float lights and flowers. A battery-operated candle won't blow out in an evening breeze or scorch the edges of flower petals.