To keep your Damascus steel sword in pristine condition, clean it after each use to prevent rust and corrosion. Use a soft cloth to wipe the blade and apply a light coat of oil, such as mineral or gun oil, to protect it from moisture. Avoid exposing the sword to extreme temperatures or humidity, which can damage the steel. Sharpen the blade with care, using a whetstone to preserve its edge. Store the sword in a dry place, preferably in a sheath, to keep it safe from scratches and environmental damage.