If a bride desires a hand tied bouquet (very popular at this point) I usually make a "mock" hand tied. This looks like the real thing, but gives the all important water source for the fresh wedding flowers.
Today's bouquets have to hold up much longer than just a quick trip down the aisle. There are extensive photo sessions (especially outdoors) that can cause the flowers stress.
Once of the best professional products is a roll of florist clay.
This product is very stick and adheres to the bouquet handle, allowing you to press the clean stems against it and hold in place until they can be tied or wired into place.