I use baby grade mineral oil, just a dab of it on a cloth. This is after removing any really stubborn grease spots, etc., with dishwashing liquid on a damp cloth. It helps to always rub with the grain. Next time I will be sure to purchase "print resistant" SS appliances!
Mineral oil is the only thing I have found that restores a luster to the SS. Regular mineral oil is too thick; I go to the baby section of the pharmacy and get the most unscented baby mineral oil I can find. A little goes a long way, but it takes buffing (elbow grease).