What you'll need:
Cloth or rag
Wood planks (pine is a good choice)
L brackets, medium and small
Two-hole pipe straps
Clear sealing wax
What you'll do:
1. Start with the basics. Check out the wooden ladder. It needs to fit into the place you've made for it, and there must be enough room for the shelves to stick out on either side. You’ll also need to sand down any rough spots. Wipe it down after to remove sawdust and dirt.
2. Make it pretty. Now is also the time to paint the ladder if you choose to do so. Wait to paint the shelves until they've been cut to length.
3. Measure up. The planks will need to be cut in different lengths to fit on the different levels of the ladder: long at the bottom, short at the top. Get your measurements together and ask your local big-box home-improvement store to cut them for you.
Some suggested lengths:
23 inches, 30 inches, 40 inches, and 48 inches
13 inches, 14.5 inches, 16 inches, 18 inches, and 20 inches
It all depends on the size of your ladder!
4. Get the shelves on. Starting at the bottom with the longest plank, slide the shelves across the ladder's rungs and use the level to check that they are flat. Then attach them onto the ladder's crossbars, using wood screws on the steps and the two-hole pipe straps on the rungs. If your ladder has a folding platform at the top, open it and secure the smallest shelf to both the platform and the ladder rung with the wood screws.
Helpful hint: If you choose not to attach the shelves to the ladder, then 1) be extremely careful when you take items on and off the shelves; 2) don't have the shelves stick out so far; and 3) you'll have a very portable set of shelves when it's time to move them!
Rub the sealing wax over the shelving unit with a clean, dry cloth, following the directions on the tin.
5. Secure the ladder to the wall with the larger L brackets. This is, of course, optional, but if you have kids or pets in your house, it can save you a lot of worry and possibly prevent injuries.
6. And finally … Decorate! Books, knickknacks, a dry bar, or your favorite collection can now be beautifully displayed.
Sources: The Kitchn | HGTV