Apologies if this has been asked before, I couldn't find it in the FAQ or the search.
I learned in my intro East Asian history class that the terracotta warriors were made out of moulds in order to speed up production. (I think my prof mentioned there were 7 or 8 different molds). But I recently watched a "documentary" on Netflix that stated they couldn't have used moulds because a) there are too many unique faces and b) they used a method where they coiled the clay (supposedly shown by the inside of a broken warrior).
I'm inclined to believe my prof but not I'm not so sure.
This had been one of the various theories, and the more prominent one for quite a while (this sort of "assembly line" system). But more recent scholarship has been leaning towards these pieces being individually wholly crafted by artisans, each unique. For more info, this natgeo article provides some good background. There's still quite a bit of work to be done in analyzing the Warriors and methods of manufacturing though, so nothing is fully set in stone yet.