I recently made these shelves for my tiny art studio. I wanted something I could take with me to the many different spaces I'm sure to move in the future - easy to transport and modify.
These shelves are made completely out of three sheets of ply-wood. Because the pair of boxes are slightly different sizes they easily fit inside one another, making it super easy to move. I figure depending on the space I can stack them higher, lower, split to make two shelving units, or always add more longer pieces of wood for more room.