completely stop smoking between applications. Make sure it's not windy, or the temp of the griddle won't get hot enough. I bought a cheap infrared temp gun and had mine at over 600 for the seasoning burns. I did it just inside my garage to eliminate the wind affecting it. I did 5 coats, and after it cooled down it was if it had a teflon finish. Hard, smooth and not at all sticky.

When you clean the griddle after cooking, scrape it clean and only use water sparingly on stubborn spots. Wipe on another think layer of oil and put it away. I use regular canola now after it's seasoned, some people complain that the flax oil can give off a fishy smell/taste. I didn't experience that, and even so, it dissipates the more you use it. I don't like to cook with flax.

If you bought a flattop that's cold rolled steel, like Blackstone, this guy explains it well:

https://www.youtube.com/watch?v=tuX7IAWGiOA