Basement bathroom door for cleaning supplies. Kitchen to basement door for pantry items. Back of girls' door for barbies. Inside girls' closet for shoes. Inside my closet door for belts and scarves. Entry door for shoes, mittens, etc.
For even more storage, consider hanging shelves up high that run the length of the room. You won't loose any floor real estate at all, and you'll gain a lot of storage space. Design Dozen: 12 Clever Space-Saving Solutions for Small Bedrooms
No room for a nightstand beside the bed? Hang shelves on the wall instead. In the room above, wall shelves provide a catch-all for books and other sundries in a super-narrow sleeping space. Design Dozen: 12 Clever Space-Saving Solutions for Small Bedrooms