One thing about the Asian pot makers on Youtube. They make it look easy. It ain't easy! You don't appreciate the subtle angle adjustments of the smoothing tools until you have one in your hand trying to get a smooth, even finish on wet concrete. The easiest rustic pot technique is the draping method. Soak a towel in a slurry of cement and sand and lay it over ( or inside) a suitable vessel. You can make 10 a day. The most detailed and custom shaped pots use damp sand as the inside form. Concrete is applied to the outside and shaped with different tools. It's by far the hardest technique, requiring skill achieved after quite a few fails. Ask me how I know.