Consider ordering an extra boutonniere.

Some florist include an extra boutonniere, if they don't, make sure that you order one. They can break easily. In a pinch I have made a boutonniere by taking a flower from one of the bouquets. The grooms boutonniere can really take a beating with people hugging him.. Consider ordering an extra one for the groom.

Make sure that the person receiving the flowers has a list of what to sign for.

If you are having your flowers delivered somewhere other than where you will be, church, chapel, reception hall, make sure the person receiving them knows what you ordered.  How many bouquets, boutonneres, corsages and other.