Convert bookcases into a custom store-and-serve buffet. Using wall anchors, hang a pair of bookcases horizontally while placing a third on the floor directly below. Mount the middle bookcase at counter height so it can be used as a serving station for cocktails. Would prefer it with "ends" between the two bottom pieces to make it look more finished, and maybe some glass doors
Make space for supplies over the bathroom door. 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.