After the design is finished, take care to store them in a vase or container that doesn't press or crush the flowers up against each other or store the pressed against the wall of the refrigerator. If you are using a bouquet holder that doesn't have a self wicking handle, be sure to dribble fresh water onto the bouquet holder each day since the flowers drink a great deal of water each day.
It is important not to ever let the foam go dry. The life of your flowers are dependent upon the fact that there is a continual water source once inserted into the foam.
I usually use Floralock Stem Adhesive into my bridal bouquets to keep the flowers locked into place in that wet foam. Be sure to shake the aerosol can thoroughly for at least a minute to be sure the adhesive is able to be completely used. Keep the nozzle clear, wiped off continually and rinse out after each use. If the red stem gets clogged, you can snip off the ends shorter if necessary to free up the nozzle.
I always use the Flower Sealant like Finishing Touch. Air conditioning and household refrigerators pull moisture OUT of the air. Professional flower coolers add IN 80% - 90% moisture. The flower sealant helps keep the petals hydrated and seals the petals to slow down transparency.