As someone that loves cooking & uses their cast irons alot I have some tips I've picked up over the years:

1. It's cast iron it doesn't care
2. It's cast iron it doesn't care
3. Flax Oil (the refrigerate after opening kind is best for this i think?), for me at least, is the best oil to use for putting on some seasoning.
4. It's cast iron it doesn't care
5. Do not leave in the sink - wash it and dry it and get it outta there asap
6. It's cast iron it doesn't care
7. Wash it with soap & water. "oh it'll strip the seasoning" you know what else strips the seasoning? Getting a hard sear on a burger or a steak. Making hotdogs. Day to day use of the cast iron pan. You are going to need to add a layer of seasoning sometimes and you just have to learn to live with it.
8. I'm the baby gotta love me
9. That shit with the kosher salt, vegetable oil, and a paper towel? Don't bother. Soap. A scouring pad.