This tutorial by the Floral Design Institute demonstrates how to create a hand-tied Calla bridal bouquet. The key to creating this bouquet is to make sure your flowers are properly prepared. The flowers should be fully hydrated (in water for at least two hours). Take each flower and mold each stem to to reflect the natural curve of the flower. Lay them side by side so they are lined up in a parallel fashion. Give even pressure on the stem to prevent bends or kinks. Some stems may be straight so you can use those flowers toward the center of the bouquet. You can begin to stack the flowers placing all the flowers at the same level and grouping the curved stems together. After your last flower is placed, check the Callas to make sure they are level. To tie them, use raffia. This type of material doesn't weaken or stretch when it gets wet. Gather the Callas together gently and lift them up. Give them a gentle shake to create a rounded shape. You can adjust the height and turn the faces to be where you want them to be. Take the raffia and hold it in the center of the bouquet with one finger. Wrap it around the stems a few times and tie it off. Next, you need to cut the stems. Measure the stems to be about two hand lengths long. Because the sap can stain a dress, you need to seal the stems after you cut them. Dab on clear nail polish to the end of each stem, one at a time and let them dry. Next, ribbon wrap the stems. Extend your ribbon off the top and begin wrapping securely at the base leaving the stems exposed to create a natural look. Work your way upward, overlapping the ribbon as you go. When you get to the raffia, cut it off then continue with the ribbon. At the top, cut the ribbon and tie the two hanging pieces in a knot. Use the tails of the ribbon to attach a bow. This Calla bouquet will last a long time and add beauty to your event.