Clay can be a pain to collect in large amounts, and to use as a practical building block. My idea is to add another source of clay that isn't too OP: Rough clay.
Rough clay would spawn commonly in the dirt layer, under deserts, and on the surface in mesas. Rough clay would be light brown, and smooth, and spawn in chunks of 4 to 10. Each block would drop 1-3 rough clay balls. Smelting them would yield a single brick, and crafting 4 rough clay balls will give a rough clay block. Rough clay blocks can be turned into normal clay by crafting it with a water bucket. Thoughts?
You should have to use a cauldron on rough clay balls (like potions) and then they turn into normal clay balls, then can be made into bricks and brick blocks, instead of the other way. This is a bit easier instead of all the rough bricks and rough clay blocks.