There are million anecdotal methods on how to care for cast iron, but this TL;DR works for me: Use some kind of oil when you're cooking. Hand wash them and never put them in the dishwasher. And coat with a thin spray of olive oil (the "oil only" sprays are great) after use and buff with a paper towel. Never leave anything on the iron surface except a light coating of oil. Don't let them air dry. That works for me! :-)