We started by creating coils- about 10 each. It didn't matter the length- if one broke they kept it.
Each student then received a glass bowl lined with plastic wrap (this allows the clay to be removed from the bowl without sticking). Students placed the coils inside the bowl. They could do different patterns such as spirals, zigzag, or even parallel lines. Once the bowl was filled with coils, we put little clay balls in the openings to "plug up" and spot where liquid might leak through. Lastly, we smoothed out the inside of the bowl by smearing the coils.
I allowed the clay to dry for a few hours before removing it from the glass bowl and added students names to the bottom using a needle tool.