Mix all ingredients in a saucepan over medium heat, stirring constantly until mixture is dough like. If adding colour, add to the water then mix water through.
Once mixture is thickened, turn into a bowl. Cover with a damp paper towel and let cool.
To make shapes, knead the cooled mixture until smooth. If the mixture is a little sticky, add a little more corn flour. Shape the clay as desired, then follow the air drying or baking method to dry out the clay.
If air drying: Leave overnight, turning over once to ensure both sides dry evenly. If baking: Preheat oven to 160°C. Place shapes on tray lined with baking paper and bake for approximately 30 minutes. Check the shapes regularly for the last 10-15 minutes to prevent over browning.