Apply a few drops of lubricating oil to the blade. Rub the oil so it coats the entire blade, and let the oil sit for a few minutes. Place a drop or two of oil in the hinges if your knife is a folding knife.
Wipe the oil away from the blade with a soft cloth. If any rust or dirt remains, add additional oil, and allow it to sit again.
Sharpen the blade of the knife with a whet stone. Use quick strokes, sliding the blade from the handle end to the tip.
Wipe down the entire knife with a clean, soft cloth, and store it in a case.