The key to improving or preserving wood furniture by refinishing it is to prepare the surface properly. The National Paint and Coatings Association advises that it is not only easier to correct faults and repair blemishes before finishing, but doing so will guarantee good results.
The first step is to remove the old paint and varnish. A paint and varnish remover softens the old finish so that it can be scraped off easily with a stiff-bladed scraper or putty knife. The nonflammable, wax-free semipaste type of remover is the best for do-it-yourselfers. Be sure to work in a well-ventilated area and wear rubber gloves.
When bare wood begins to show through, switch from a scraper to steel wool to protect the surface. Follow the grain of the wood as you go.
After the finish is gone, wipe the surface down with an old cloth. If you used a wax-based remover, dampen the cloth with soapy water or the solvent recommended by the manufacturer's label to remove any residue.
Be sure to repair scratches, which often can be removed with light sandpapering using fine-grade sandpaper. Deep scratches may require the use of a sander. Dents can be removed by wetting the area with a few drops of water, letting the water soak into the wood so it expands, and sandpapering with fine finishing paper to even out the surface. If the dent or scratch does not respond to this treatment, try using sparing amounts of filler such as plastic water putty, wood compound paste, plastic wood, or glue and sawdust putty.