Flowers.  One of the best ways to save money is to do your own flowers.  If want to save even more...make them yourself and get creative with it.  One of my favorite bouquets of all time was dried wheat wrapped around dried poppy was only $15 at the farmers market!  For Jen and I's wedding we actually made our own out of fabric, paper, sola flowers (balsa wood), and old negatives I had lying around.  This saved a ton of money, made it our own and allowed us to get them done way in advance.  Added bonus...dried or made flowers will last forever...ours are currently the centerpiece of our dining room table :).