I recommend using oil with a high smoke point such as coconut oil, avocado oil, or vegetable oil. I also often use extra virgin olive oil (with a smoke point of 375 F) for recipes up to 400 F and have had no issues so far. Avoid aerosol cooking spray like non-stick Pam spray as it wears away the non-stick coating in your air fryer basket. Instead, using an oil mister is best.