Thread the upholstery needle with 24 inches of upholstery thread. Knot the ends of the thread. An upholstery needle is a special curved needle used is situations where you cannot reach both sides of the fabric. Upholstery thread is thick, strong thread. Both are available in fabric stores.
Pull the remaining thread tight if the button is attached and hanging loose. Stick the needle into the fabric directly behind the button, picking up 1/4 inch of fabric. Bring the needle through the shank, or wire loop, on the back of the button and push it through the fabric behind the button again. Pull the thread tight.
Stitch through the fabric and button several times until the button is securely attached. Pull the thread tight each time. Knot the thread and cut off all loose threads, leaving 1/4 inch of thread to prevent the knot from becoming untied.
Reattach new button or a button the has come off entirely in the same way. Dab a bit of white glue on the knot to keep it from becoming loose.
Measure your remaining buttons and buy a button covering kit with buttons the same size. Cut out the proper size pattern from the back of the kit.
Steal a small piece of fabric from an inconspicuous spot on the chair or from an unused arm cover. You might find this fabric on the underside of the sofa or on the back of the skirt.
Use the pattern to cut a circle of fabric. Place this circle right side down over the plastic button mold. Press the top of the button into the mold, keeping the fabric even on all sides. Be sure there are no folds in the fabric. The button mold is a cup-shaped circle of soft plastic that is used to shape the fabric on the button.
Tuck the edges of the fabric smoothly and evenly into the top of the button. Place the bottom of the button on top of the folded in fabric with the shank up.
Place the round tool included in the button kit over the shank of the button, centering it carefully. Press down on the tool until the back of the button snaps securely into the top of the button. Remove the button from the mold by pressing up on the bottom of the mold.