How can I organize my small bathroom to make better use of space?

Capitalize on vertical space. Floating wall-mounted shelves, recessed built-in shelves, over-the-toilet cabinets, and full-height linen cabinets add storage without encroaching on floor space. A vanity with drawers and pullouts (rather than open-door cabinets with single shelves) roughly doubles usable storage in the same footprint.