(Go ahead, look up the word in the title. Or just click here.)
There's a great article in the Indian Economic Times this week by Vikram Doctor about how dietary restrictions lead to innovative cooking and great food. The author invokes Kosher, Jain, and other religious based restrictions on food preparation and consumption that lead to innovative and creative dishes.
I've often remarked that I didn't really learn how to cook until I went vegetarian. Set up some restrictive parameters for your own cooking for a month and see what it forces you to try.