The Iron Man stool pieces have cuts on both sides, what I do is draw lines around corners with a pencil on the wasteboard, and use centre zero point. I used a small bit to cut the logo, and filled it with epoxy mixed with glow in the dark paint, but the glow paint I got on Amazon doesn't work. Most of my designs start with 1x6 planed lumber, then glued together for desired width. This allows for easy calculation of costs since most of my projects are sold via Facebook. All of my step stools can be easily glued together due to pockets in the right places, these stools have an 11 degree slant on legs, which requires the to and bottom edges to be trimmed on a table saw.

full plans available here

https://www.etsy.com/ca/shop/HandyHusband