The process is simple, but it may take some time.
Step 1- Trace out a bunch of circles onto posterboard. I used a QT cup to make sure the circles stayed consistent. (If you're not familiar with QT, I'm so sorry. It is only the best gas station in the world! Yes, it's that good!)
Step 2- Cut the circles out. If you have a circle die cutter this first part can go really fast, otherwise it will take a while.
Step 3- Spray paint the circles if they are not the color you want already.
Step 4- Install the circles. Make sure your first row is straight/level. I used thumb tacks to stick my circles to the wall. Some people are completely against putting holes in their wall, but it's so easy to fix I don't mind at all. I also like that it allows the poster board to come away from the wall a bit and provide a nice texture.
The second "tier" should be applied as shown below (halfway down the first row and off-centered). You can see that as you apply the second row of circles, the thumbtacks on the first row are covered.
Continue this process all the way up the wall. At the top you can either spray paint the thumb tacks to blend in or use some spray adhesive on the back of the circles.
Pretty soon you'll have a beautiful fish scale wall! :)
If you use this tutorial I would love to see pictures!