Here’s so far the best seasoning method for cast iron that I’ve found after having tried multiple ones and not having too great of a success. It can’t be overstated how important it is to remove all excess oil. It doesn’t take much to ruin the results.

• Wash with soap and hot water.
• Dry thoroughly.
• Immediately into a 100 degrees C oven for 20 minutes.
• Heavy coat of oil. Canola oil works fine.
• Wipe ALL of it off. First with a cloth, then with a paper towel.
• Put back into the oven and let it warm up to 150 degrees C. Then take out and wipe with a paper towel once more.
• Back into the oven and let it heat up and bake at 250 degrees C for an hour.
• Let it fully cool after each layer.
• For the first treatment, at least 3 layers are needed. Five is even better.