I wear heels often, with my dressy casual outfits. I think they work best with jeans to create the casual vibe. The jeans can be colored (I wear olive, black, and white jeans in addition to various shades of blue). I'm attaching the shoes that I wear casually most often.
ETA: I put up a couple more finds. Last night, I went out and wore heels casually. I wore cropped jeans (medium blue), a striped top, and the brandy Cole Haan heels.