Cut three broom handles to a length of 24 inches each. Measure 10 1/2 inches from the top of each leg and mark the spots with a pencil. Drill a hole all the way through each leg at the pencil mark.
Drill a pilot hole in the center of the top of each leg. This is for mounting the seat later. Sand the legs with a fine-grade sandpaper to ensure a smooth surface, stain or paint the legs and allow to dry.
Thread a bolt through two of the legs, with an eye-hole bolt in between and washers on both ends. Attach an acorn nut to the end of the bolt. Put simply, you should have the following: bolt, washer, stool leg, eye-hole bolt, stool leg, washer, acorn nut.
Insert the eye-hole bolt in the center of the first two legs through the hole in the third leg. Attach a washer and acorn nut. Tighten the nuts so that the legs are secure while allowing enough movement to fold the legs together.
Position the stool as you would if you were going to sit on it. Measure the distance from the top of each leg to the next. Place a piece of leather face down on a flat surface, mark the appropriate measurements on the leather, and cut out.
Position the leather seat on top of the stool legs. Place a finishing washer onto the top of the leather and push a 1-inch wood screw through the center of the washer, through the leather into the pilot hole in the first leg. Repeat with the other two legs and your stool is ready for use.