Change the look of a basic bar stool by making a cushion to fit on top of it. You don't have to sew to make a bar stool cushion, as you'll attach the fabric to the stool with a staple gun. Use a piece of foam for a softer cushion, or a thin layer of batting for a stool without much padding.
Turn the stool upside down and use the pliers to pull out the staples holding the current upholstery and cushion in place, if necessary. Peel away the fabric and cushioning, then discard.
Place the upside down stool on top of the piece of foam. Trace around the stool with the marker, about half an inch from the edge.
Use the electric knife to cut the foam out. If you don't have an electric knife, cut the foam with scissors.
Turn the stool right side up. Spray the top of the seat with adhesive. Either open a window or go outside do this, so that you have sufficient ventilation.
Center the foam on the seat of the stool against the adhesive and allow it to set into place.
Spread the fabric on the floor, underside up. Lay out the batting on top of the fabric, then flip the stool over and rest it on top of the batting. The foam and seat of the stool should rest against the batting.
Fold the edges of the fabric and batting over to the underside of the seat. Pull the fabric and batting taut, then staple in place along the edges of the underside of the seat. Staple on the left side, then the right side, then the top edge of the seat, then the bottom edge. Continue stapling in that fashion around the edge of the stool.
Trim excess fabric and batting away, leaving about half an inch extending beyond the staples.