Here is the ultimate Do-it-yourself wedding idea: as your guests enter the ceremony venue, give each of them a flower. Or you can even ask each guest to bring a flower as a gift!
Then, when you walk down to the altar, you can stop and collect a flower from each guest...assembling your community bouquet as you go.
This gives you an awesome opportunity to involve each guest while building the ultimate do-it-yourself bouquet. I like this way better than a receiving line.
*Recommended Reading*
(Fun book full of great advice!)
