Wash the cooking surface with warm water and a mild soap if needed
Dry the griddle completely
Turn the heat to high until the surface starts to darken
Apply a thin, even layer of high-smoke-point oil
Use a paper towel or cloth to wipe off all excess oil
Keep heating until the oil stops smoking
Repeat the oiling and heating process several times
Let the griddle cool slightly between coats if needed
Season the sides and edges as well
After each use, clean the surface and apply a light coat of oil
Store the griddle in a dry place