[omnicognate]

The typical cooking uses to which a skillet is put season it automatically, because it spends its life being oily. The polymer coating known as "seasoning" forms naturally from long contact with oil (even without heat). So the idea of seasoning being something you have to put on the pan and then maintain is wrong. You can explicitly "season the pan" as a sort of bootstrapping to get that layer started off quicker and protect it from rust in the early days, but it's optional and doesn't need maintaining afterwards. An alternative to protect it from rust (and encourage the formation of the polymer) when it's new is to brush it with oil before putting it away. Once it's broken in (you'll know) it doesn't require special care. You can scrub it, use washing up liquid, whatever.

If you do season the pan, the most important thing is to wipe off all the oil after applying it. You brush the oil on and then wipe it completely dry. It should be dry to the touch and matt, not shiny. You should not be able to see ANY oil. The microscopic invisible bit of oil left is all you want. Only then do you heat it. The temperature doesn't matter much. 180 C or so in an oven is what I've used. The kind of oil used also doesn't matter. For best results do the whole thing 3 or more times. If you bake a visible layer of oil onto your pan you're not seasoning it, you're just covering it in burnt crap.

And it's optional!

Note that the above is for skillets, which self-season because they're used for frying. (Hence "seasoning" - i.e. using them for a while.) The story is very different for some other things. For example, we have a dutch oven used for baking bread, which is not an oily process. For that you really do have to season. Ours came pre-seasoned but it rusted after an unfortunate baking mishap and I had to electrolyse it and then give it 5 rounds of oven seasoning (as described above), after which it has been a zero-maintenance workhorse.

Griddles are absolute fucking bastards and will ruin your life.

If you ever do electrolyse any cast iron (it's great fun and will restore anything), A) pay a few quid for graphite electrodes (overgrown pencil leads, available on Amazon), rather than using an old stainless steel knife and producing hexavalent chromium (Erin Brockovich's favourite chemical) and B) use a bench power supply because nobody sells the kind of car battery charger all the online tutorials tell you to use any more (they're all pulsed ones now, completely useless for electrolysis).