So, this one is an oldie, from my first apartment.
I needed a shelving unit for my porch, so I can up with this easy ladder shelf.
To make it, you need need 1 by 4 boards cut to the width you want (have the people at the store cut it to size for you if you don’t have a saw), clothes line, an o shaped ring that is fit to hold weight, a hook for the ceiling that can hold weight and a drill.
First, paint or stain the wood the color you want. If you are going to keep it outside, I recommend treating the wood in some ways.
Then, at the corners — one inch from each edge — drill a hole that is slightly smaller than the clothes line you are using. You want to be able to still get the line through, but you want it to be tight so there is friction to help keep everything in place later.
Next, cut the clothes line into two lengths that are double the height you want the shelf to be plus two feet. Use a larks head knot to tie center of the string to the o-ring. You should have four strings hanging down from it. From there, thread them through the four holes on what will become your highest shelf. When the shelf is at the height you want, tie and overhand knot under it to keep the shelf in place. Repeat until all the shelves are in place. Then cut away the excess string or leave it. Your choice.