I look at smartphone cases all the time and am constantly "oohing" and "ahhing" at every pretty one I see. I naturally gravitate to the more feminine cases and have been really impressed by a handful of ones I've seen recently.
Amy Sia: I'm a fan of Amy Sia's work and love how Society 6 turns artwork into phone cases. Sunset Storm is my favorite piece from Amy. It's a beautiful blend of bright colors that are surprisingly soft on the eye but still very cheerful with all that color.
BlissfulCASE: I've been obsessed with colorblock lately for jeans, skirts, dresses — you name it. BlissfulCASE is a collection made by two designers in Brooklyn whose designs are "authentic, childlike and made by free hearts." They have a gorgeous set of cases incorporating colorblock and wood prints that give the smartphone a rustic vibe that I adore.
Velvet Owl: On the other end of the coast, Velvet Owl is a design studio in California that gets design inspiration from Cali and the Pacific. My favorite is their Bodega Bay case that reminds me of the ocean and sand. It's available for the iPhone 4, 4S and 5.
Polka Dot: I'm almost as obsessed with polka dots as I am with colorblock. I like this one because it's subtle, with smaller dots, and is in that pretty Tiffany blue.
Running on Happiness: As a writer, I always appreciate the beauty of a written word or phrase. Kate Spade offers a great variety of iPhone cases with cute little phrases, but I also discovered this one for Nexus phones.
(Images: as credited above)