Mill the parts
Cut rabbets and dadoes
Set up your dado to cut a 3/4-in. wide and 3/8-in. deep groove. Cut a dado 10-in. from the bottom of each side for the bottom step (C). To cut the top rabbets, clamp a sacrificial plywood fence to your saw’s fence, so you can slide it right up against the blade. Cut the top rabbets.
Make a template
Draw the side’s shape (see Fig. 1) onto a piece of 1/4-in. or 1/2-in. plywood. Clamp the board to the workbench and cut the shape with a jigsaw. Sand the template (E) up to the line. Take your time, making the template as perfect as possible. Any imperfections in the template will show up on the finished sides.
Rough Cut Sides
Trace the template onto the inside face of each side. Be sure to flip the template over when tracing the second side to create left and right pieces. Rough-cut each side, staying about 1/4-in. outside the line.
Rout the sides
Pin the template to one of the sides with 3/4-in. 18-gauge brad nails. Keep the nails close to the edge of the template to prevent it from lifting while you’re routing. With the side clamped to your bench, trim the edges flush with the template using a top-bearing flush-trim bit with a 1/2-in. shank. Remove the template and brad nails and repeat on the other side board.
Scribe the step angles
Clamp the stool together without glue, with the bottom step overhanging the front and back of the sides. Set the top step flush with the back of the stool, letting the front edge overhang. Transfer the angle from the sides onto the ends of the steps.
Bevel the steps
Tilt your table saw’s blade to match the scribed angles on the steps and then rip them to final width.
Assemble the stool
Glue the dadoes and rabbets and then clamp the stool together, checking for square. Clean off any excess glue with a damp rag.
Drill dowel holes
When the glue has dried, remove the clamps and mark for drilling the dowel holes. Space the dowel holes evenly, centered on the steps thickness. Drill the holes 2-in. deep using 3/8-in. bit. I used a Forstner bit to prevent tearing out the plywood’s veneer.
Glue and insert a dowel into each hole. The dowels should be just proud of the surface, so you can trim them flush after the glue dries. Trim the dowels using a handsaw. To protect the surface from the saw’s teeth, cut a hole in a piece of cardboard or plastic and slip it over the dowel. Finish up by sanding.