I always use a stem adhesive called Floralock to secure the stems into the wet foam. Do not use this product until the design is completely done, because it is difficult to insert more flower stems after this covers the foam.
Be sure to shake the can thoroughly and follow all the direction for use listed on the side of the can.
I mist all my flower designs with a flower sealant such as Finishing Touch. This is especially important for flowers that can't be stored in a professional florist coolers.
Regular air conditioning and kitchen refrigerators pull moisture out of the air. Professional flower coolers put moisture into the air. Keeping the flowers hydrated slows down petal transparency and early wilting.
The final bouquet shows the true beauty and elegance of Oriental lilies. Keep in mind they are also available in white and various shades of pink.
Check out all the wedding flower tutorials, including bouquets, corsages, boutonnieres and reception centerpieces.