Hang ‘Em High
Put the clothes bar as high up as you can by moving it as far to the front of the closet space as possible. Leave just enough room to close the door.
Behind the hanging clothes, build shelves from ceiling to floor with cubbies in them to hold different items. The top shelves will be shallower due to the slant, and you can use those for shoes — toes toward the back wall — and small items like gloves or jewelry in little boxes.
Keep off-season clothes in bins in the deepest space. If you stack shallow bins in progressively smaller sizes on top of one another, you can fit more bins in the slanted cubbies.
Inexpensive, ready-made shelving components are designed with slanted backs for just this problem. Measure the space and the angle of slant carefully to determine how well a pre-made closet system will fit.
You may need to dust off a few basic carpentry skills to adapt the units to your particular slant. If you have to shave off the back of top shelves, cut them so they fit right up against the slanted ceiling, and the house itself will become the back of the unit.
Buy a system that incorporates some hanging storage for clothes that can’t be folded. Put a shoe rack or storage bins under the hanging clothes.
Closet for Two
Build a vertical shelf unit with sides down the center of the closet space that uses all the room. Keep folded clothes like shirts, sweaters and jeans in the enclosed shelves.
Attach two short hanging bars, one on either side, to the shelf unit and the side walls. Behind the hanging clothes, on the floor and in the deepest part of the slant, keep lidded boxes for seldom worn or off-season clothes.
Sacrifice Some Floor Space
Extend the closet a foot or two into a bedroom so there is enough height to hang clothes. Position shelves along the back wall for handbags, hats, boots and other items that can be stowed.
Clutter-free bedrooms seem more spacious even if the closet intrudes into the room.
Organize the Closet Under the Stairs
In a closet under the stairs, put hooks on one side for jackets and rain gear. Keep sports equipment, off-season boots and other bulky items in plastic milk crates pushed back under the slant.
Tuck a boot tray and an umbrella stand in the open space.