Rather than clutter a single hook with several sets of keys, make a custom board that gives each set its own clearly labeled space. To make the board, have a piece of Homasote fiberboard cut to fit into a picture frame. Cover board with a piece of linen, and staple it at back. Tuck the board into the frame, then nail on labels and attach one screw hook for each set of keys.
Martha Stewart Living, August 2006