You may be tempted to fill your windowless hallway with framed artwork and photographs. After all, added visual interest might distract from the close quarters and lack of light. Tread carefully, though, as you risk calling attention to the same imperfections you're trying to conceal. Keep the mood controlled and unified by ensuring that at least one common element, whether it's a color or a texture, appears throughout your hallway design. In other words, choose a theme and stick to it.