Clear out the inside of the armoire. Remove all but the center shelf. An armoire intended for use as a wardrobe will probably not have a center shelf. In this case, build a center shelf by cutting plywood to fit the space. Screw L brackets to the inside of the armoire for the shelf to sit on. Sit the shelf on the L brackets, and screw it into place.
Use a hole saw to cut a two-inch diameter hole in the shelf at the center back for electrical cords. Cut a 3-by-3-inch square hole in the back of the armoire just beneath the shelf. Sand the edges of both holes smooth.
Measure for shallow shelves above the center shelf. Cut stock shelving from the home improvement store to the proper length, and attach the cut shelves to the armoire with L brackets. Make one shelf at least a foot tall to hold most standard liquor bottles. Make the second shelf tall enough for your glassware.
Create a waterproof surface on the shelves with several layers of polyurethane. Apply the polyurethane with a paintbrush, and let it dry completely before adding another coat. Refer to the label for guidance on how long the product you're using will need to dry. Alternatively, use rubber shelf paper to prevent glasses and bottles from slipping.
Decide how you will use the space under the center shelf. Beer aficionados should install a keg and tap, a kegerator or a dorm-size fridge. Oenophiles should consider a wine cooler and wine rack. Run the electrical cable from the back of the cooler through the hole in the back of the armoire to an electrical outlet.
Furnish the center shelf with your drink making equipment, such as a blender, ice bucket, ice crusher or juicer. Run the cords through the hole in the back of the middle shelf and then through the hole in the back of the armoire.