If you have a big family and/or group of friends that will all be getting married within a few years of each other, why not share wedding decorations. For instance, one person could buy a wishing well and lend it to the others in the group when they need it. You can do this with many wedding decorations. Try to get something that won't be out of style next week either.
Look through bridal magazines to try to find favors and decorations that you like, that you also feel you could make. If you're not crafty, maybe you could get a friend or a relative to do it for you.
At http://www.todays-weddings.com/articles/favor_ideas.html you can read an article about 25 wedding favor ideas that you can make yourself.
Go to http://www.onlinefavors.com/ to find unique wedding favor ideas to purchase and/or make. There's a section on the right-hand side of the page with links to do-it-yourself favors.