It's pretty much exactly like seasoning a cast iron pan -- get the grill grates screaming hot, switch off the heat, sop up a paper towel in your high-heat oil o

It's pretty much exactly like seasoning a cast iron pan -- get the grill grates screaming hot, switch off the heat, sop up a paper towel in your high-heat oil of choice (eg: canola oil) but not dripping, and wipe your grill grates. This is generally only possible with a cleaned grill and it would be prudent to clean your grill after it's heated up and before you apply oil.