Pick out 10 to 12 calla lilies, making sure they are clean, fresh, healthy and as uniform as possible.
Use floral tape to bind two flowers together at the stems beneath their buds.
Add more lilies as you go, building around the center. Bind the stems with more tape so that the bouquet is secure, taping over the same spot.
Mist the flowers with water as you build your bouquet to keep them hydrated.
After all the flowers have been bound together with floral tape in the arrangement you prefer, use the flower clippers to cut the ends of the stems to a uniform length. Be sure to cut the stems at an angle.
Secure with a wide ribbon, wrapping the ribbon over the tape. You can either simply cover where you've taped or wrap the entire stems in ribbon.
Use a pearl- or crystal-headed pin to fasten the ribbon. Broaches can also be used for a more decorative finish.
To wrap the entire stems in ribbon, start at the top under the buds and work down, wrapping as you go. At the bottom of the stems, tuck the ribbon over the ends and work your way back up the stems, tying a bow if you prefer. Secure the ribbon with pins or a broach.
Refrigerate after completion to keep the flowers fresh.