A few years ago, I decided to cast my pieces into plaster molds. Be careful, this does not mean that it is simpler when it comes to making molds.
First you have to make the prototypes. I favor raw earth for my cups. I turn and mold them directly without firing. For larger ceramics, I turn or model the prototypes and I biscuit them.
Of course, there are different types of molds from the simplest to some very complicated one including 20 different parts. For the moment, I limit myself to 4 parts. The idea for me is to make prints of parts that I can assemble. The Square vase, for example, is the assembly of a cup and a rectangular cube. I can decline like that to infinity.