For all those art supplies. DIY project du jour: Shoe box + toilet paper tubes (and/or paper towel tube pieces) = storage for pens and other office/art supplies (via Aunt Peaches) More paper tube repurposing ideas: here.
This is a perfect combo of my two favorite ideas for that space under the stairs leading to the basement. A reading nook AND book storage and shelves . assuming that there is enough space for this there.
The one great thing about a laundry room is you do not need that much space. Convert a closet into your dream laundry room. A stackable arrangement conserves space but you can also install side by side washer & dryer with a counter top and cabinets above.