Toiletry Shelf - Make space for supplies over the bathroom door so that they'll be accessible when they need to be replenished. Use wood screws to secure a pair of wooden shelf brackets to either side of the door frame; screw shelf to brackets. The shelf should rest on top of the door molding, which will help support the weight. Keep small bottled items and toilet paper in handled boxes. Bars of soap can be stored, unwrapped, in an airtight glass container.
Removing drywall and putting in a handy storage shelf. Another good idea if space is sort of tight and you want to display things instead of using a curio cabinet. You could add a door/doors if you wanted the items protected.