Boots: Steve Madden (also here)

These boots have buckles on both ends of the leather straps and are extremely adjustable for various calf sizes. The slouchy-ness makes them very easy to wear over jeans and leggings and even with certain skirts and dresses, depending on your aesthetic. (I might try them with shorts in the summer, but if I don’t post any pics to that effect, you’ll know it didn’t quite work out.)

See them in action here.