I wish we had a closet that we could do this in. Phil would absolutely die (and I'd avoid having zip bar in my house)
IKEA Hackers: Expedit under-stairs storage
Like that the biggest under stair space is left as a work cubby (I could see us having a butler pantry or breakfast nook). The other space is used for closets.
Keep your TV in a special spot. | 27 Genius Ways To Use The Space Under Your Stairs
Or perfect little cubby holes for everyone in your family.