Wash the broken pieces gently in mild dish soap and warm water. This removes dirt and oil that may prevent your pottery from bonding properly. Rinse the pieces under running water and dry them on soft, clean cloths.
Open a bottle of PVA (polyvinyl acetate) white glue. Dip a paintbrush into the glue, getting just a little on the tip. Coat the edges of the broken pieces with the glue. The layer should be thick but not dripping. If you have more than two broken pieces, join together just two pieces at a time.
Press the pieces together, lining up the edges exactly. Hold the pieces together for about 60 seconds. Avoid shifting the pieces; this will grind away small pieces of pottery and you'll need to start over.
Fill a plastic tub with dry rice. Gently stick the edge of your piece down into the rice so the joined pieces are upright. This allows the break to join without gravity interfering.