The first technique, and the most popular, is using stickers. These need to be stuck onto the white bisque before any paint is put on, we have stars and hearts to choose from. Once stuck down, two layers of paint are applied. The great part is, that even if the paint is applied crazily, in a mish mash of colours, once you peel off the stickers and the piece has been glazed and fired, you are left with white shapes in some sort of design. Masking tape can be used in the same way, to keep areas white for writing to be done, or to protect the base of the pottery (the bit you can’t get paint on). Masking tape can also be used to create great geometric designs, a really simple idea to do but it looks professional and is easy to keep relatively neat neat.
But at the end of the day, the main thing is that your child has fun so let them go to town on their pottery!