Dust the white leather couch with a soft cloth every week. Moisten the cloth slightly if the leather is finished; the couch's label should indicate whether the leather is finished or unfinished. Using a moistened cloth on finished leather picks up more dust and dirt.
Wipe up spills on the white leather as soon as they happen. Use water and a mild leather soap to clean stains on the couch.
Apply a conditioning solution to the white leather couch at least twice each year using a spray made from equal parts boiled linseed oil and white vinegar. Spray the solution on the couch, and rub it into the leather with a soft cloth. Leave it on the leather for five minutes, and then buff it off with a clean cloth.