I bought the tulle and the ribbon from theknot.com. My mom came up with the idea of glueing the tiny shell onto the bow. I got the shells from a store in Navarre on Highway 98 called Sea Shell City. There's chocolates inside that were in the shape of shells and sea horses.

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Links to beach themed favors online:
The Island Shop
theknot.com
Beau Coup Elegant Wedding Favors

TIP:
Use Google.com and search for "beach themed favors." I found a ton of useful information.