What's the best way to promote my new cake decorating business (for free/cheap)?

I recently started up a cake decorating business, Out of the Box Cakes, in Moore/Oklahoma City. I’m running the business out of my home (but I have a commercial kitchen at my disposal to bake the cakes, so it’s legal). What is a free or very cheap way to promote my business? I already have a website (http://outoftheboxcakes.yolasite.com), Facebook page, and business cards, but how do I “get the word out” in my community??