After I finish making a boutonniere, I mist it well with a flower sealant before refrigerating it. I use Finishing Touch by Floralife. This product hydrates the blooms and seals it against moisture loss. This is especially important for cut flowers (such as boutonnieres and corsages) with no water source.
Flower designs created in the home and stored in normal refrigerator risk drawing moisture OUT of the flowers. A normal florist cooler puts humidity INTO the unit, keeping the flowers better hydrated and extending the life. Misting with a sealant helps prevent petal transparency.
Never store your flowers in the far back of a home refrigerator. It is often colder in the back and you could run the risk of freezing your flowers.
I added a single pink pearl corsage pin to enhance the pink edge of this yellow rose and to further secure the ribbon to the stem. You can see how the interesting foliage creates a beautiful look in a tight cluster around the central bloom.
I carefully used scissors to trim up the rough edges of the burlap ribbon before pinning the boutonniere to the lapel of the tux.
Pin from the underside, using two corsage pins. Don't be afraid to push the pins directly into the rose head. You want to be sure that all sharp ends are buried into the boutonniere and that the flower is securely held and doesn't droop forward.
Another alternative is to use boutonniere magnets to hold the flower in place.