10 Common Mistakes That Are Ruining Your Nonstick Pans 1: Never Use Metal Utensils. 2: Never Preheat While Empty. 3: Never Use Nonstick Cooking Spray. 4: Never Use It for High-Heat Cooking. 5: Never Pay Too Much. 6: Never Rinse with Cold Water. 7: Never Wash In the Dishwasher. 8: Never Use It for Food Storage. More items... Jun 3, 2021