Don’t make my mistake and guesstimate completely wrong how many shims you’ll need. Do the math and figure out how many you'll need. I needed about 540 and they came in packs of 20.
2. Cut Shims
Once you have all the shims you need, time to cut your shims down. I secured a block to the fence of my miter saw and then was able to quickly cut all the shims down to the same length.
3. Sand Shims
Now it’s time to sand your life away. I’m not going to lie, this takes a long time!
It's best to use a belt sander and sand all edges of your shims to smooth them out and get off any rough spots so that no one gets splinters when they're admiring your wall.
Once all the shims are cut, sanded, and given a good vacuum to get rid of as much dust as possible, time to move onto actually putting the wall together.