Hey Jerranna! The Wine Tumbler Tool is probably one of our more tricky tools to use, especially for potters unaccustomed to ribs. Our resident potters suggest ensuring the clay is properly centered, and using the tool at an angle instead of perpendicular to the wall of clay. Throwing a wider vessel with a thicker bottom might be helpful for preventing a sliced bottom, since the very bottom of the cup will be the narrowest point. Also, make sure the outside of their cylinder is completely wet and use a sponge to pull the clay into the curve of the tool - this may help ease any stuttering, as friction and drying clay can pull the clay off center easily with a concave tool like the wine tumbler. Let us know if these tips make a difference. Happy creating!
