Old ladders will help you create shelves in the easiest way possible. As it will serve as a frame, you only need to add wooden planks. Choose different sizes that are proper for each level. And you can use these for anything! A ladder shelf will make excellent shoe storage. Place on in the closet or a smaller one in your entryway.
You can even create a desk using ladders! Take a look at the design below. It includes two ladders and a few wooden planks. It will allow you to have working space, as well as storage space.