Place a round, 3/4-inch piece plywood on the work table. These rounds are sold in most home improvement stores in the lumber aisle. Space four leg attachment brackets 1 inch from the edge and evenly spaced apart around the perimeter of the board. Drill holes through the plywood. Insert bolts, washers and nuts to hold each leg mount securely to the wood.
Turn the plywood face up. Spray the top of the plywood with adhesive for foam. Place 4-inch thick foam over the board and press the foam into the adhesive. Allow the glue 30 minutes to dry. Cut around the sides of the foam following the edge of the plywood with an electric carving knife.
Place quilt batting twice the size of the circle on the work table. Position the plywood circle foam side down and centered on the batting. Pull the batting to the back underside of the plywood and staple. Start at the top, and then pull bottom, left and right. Follow this pattern moving away from your starting points in each direction. Continue until the batting is completely attached to the wood. Trim off the excess batting.
Position decorator fabric face side down. Center the ottoman batting side down. Follow the same stapling pattern and technique used for the batting. Trim off the excess fabric. Screw on the ottoman legs. Legs are sold at most home improvement stores.
Stand up the ottoman and measure from the underside of the ottoman to the floor. Add 4 inches. Cut fabric twice the circumference and your measured height. Fold the bottom edge to the inside 1/2 inch and sew a seam. Fold the folded edge to the inside 1 1/2 inches and sew a hem stitch. Sew a folded 1/2-inch hem along each side.
Turn the ottoman upside down. Measure from your hem to the height measurement. Position the fabric face side down and hem side out. Staple at your height measurement close to the outside perimeter of the underside edge of the plywood. At 1 inch from your first staple, fold the fabric 1/4 inch back toward the staple. Staple over the fold. At 1 inch from this staple, fold the fabric 1/4 inch back and staple. Check your height measurement frequently. Continue around the perimeter of the ottoman.
Measure the circumference. Cut trim and then hot glue it around the joint between the ottoman top and skirt.