I don't know if most people are maxed out of the GC seals? But it would seem that is most likely to happen. In any case it was suggested that GC seals can aid crafting. So is that the best use of GC seals, after getting the chocobo and max promotions?

More specifically, what is a checklist of items to get for crafting with GC seals?

BTW I am a total noob to crafting.

Thanks.