Remove fabric from the chair. Pry away any decorative piping or ribbon with a small chisel. If there is glue, scrape it away gently with the chisel. Pull the staples away from the chair to release the fabric. Reserve the fabric to use as a pattern for the new fabric.
Check the foam and batting for any damage. If the foam is worn or tattered, remove it and replace with new 2-inch upholstery foam. Cover with an even layer of cotton batting to your desired level of plushness. Staple the sides of the batting taut to the underside of the chair's cushion or frame.
Create a pattern for your new fabric with muslin cloth. If you were not able to save the previous fabric from the chair, create a pattern by tracing muslin over the cushion. Add several inches on all sides before cutting.
Lay your pattern over the fabric and trace out the shape. To keep the fabric from shifting while tracing, pin it in place with straight pins. Cut out your new material and remove any pins. It is not necessary to cut too cleanly or finish the edges, as the uneven ends will be hidden underneath the chair.
Staple the fabric to the underside of the chair. Pull taut, starting from one side of the cushion and moving around the perimeter. Address corners and curved edges much like wrapping a present. Gather the corners together and staple tightly in place, folding over fabric as you go.
Add decorative elements with ribbon or piping. This will give your chair a finished, decorated look.