Vacuum the furniture with a soft brush attachment. Leather scratches easily so avoid scraping too hard. Vacuum the couch thoroughly to remove any dirt and debris by removing the cushions and vacuuming underneath.
Make a mixture of one part white vinegar and two parts linseed oil and wipe it onto the leather in a circular motion with a soft, clean white cloth. Cover the furniture completely. The furniture should be slightly damp, not soaked.
Allow the solution to sit on the furniture overnight.
Buff the shine back on the furniture by wiping it with a soft, dry clean cloth.
Mix equal parts rubbing alcohol and water in a spray bottle.
Spray the solution on the mold or mildew on the leather.
Allow the solution to air dry. It may help to place a fan near the furniture to speed the process along.
Scrub the stained area gently with white toothpaste and a soft clean cloth. Toothpaste will remove almost any stain on leather.
Dab rubbing alcohol onto an ink stain and dry with a hair dryer set on the lowest setting. This works wonders on ink stains.
Spray aerosol hairspray onto a newsprint stain and wipe it away with a soft, clean white cloth.