Green living blog Re-Nest advises that if you have scratches on furniture with a medium-dark or darker stain, dip a cotton swab in used coffee grounds and cover the scratches. Let the grounds sit on the scratches for 10 minutes and then wipe them away gently.
With pets and kids I know all about furniture scratches. I got to use this tip last week and it worked great on our dining room set. If you need to deal with furniture of a lighter colour, try the walnut trick we covered in the past.