It is customary to give your date a corsage or boutonniere when attending the prom. Ladies wear a corsage, gentlemen wear a boutonniere.
This tradition comes from a time period, long ago, when flowers were worn to make one smell heavenly while dancing with a partner. Frequent showers, expensive perfumes, and air conditioning were rare if available at all.
Ideally, it is nice to match the flowers to the prom attire so the colors do not clash. If the colors unfortunately do not match, you must wear them if they were given to you. In such a circumstance, the lady may choose to wear the corsage on her wrist by attaching it to a ribbon or pinned to her evening bag. No matter where you choose to wear the flowers, graciously thank your date and make no mention of the mismatch. Doing so would hurt their feelings.
Corsages and boutonnieres are worn on the left shoulder or lapel with the stem pointed downward.
If the lady is wearing a dress with spaghetti straps or no straps, the corsage may be placed on the left side of the top of the bodice, on the left side of her waist, on her left wrist, or pinned to her evening bag. Pictured is a wrist corsage from Teleflora.
When pinning a corsage or boutonniere on, the pin goes into the fabric on the left side of the flower as you’re facing it, back up through the fabric on the left side, over the stem of the flower at an angle, down through the fabric on the right side of the flower as you’re facing it and back up through the fabric on the right side with the point of the pin hidden under the flower. Use two pins in an X formation if the flowers are unusually heavy. The pin will always go over the stem of the flower, never through it.