Mix 2 parts of plaster powder to 1 part water. If you need 3 cups of liquid plaster, for instance, measure out 2 cups of plaster, dump them in the bowl, then measure out 1 cup of water and dump it into the bowl. Stir with a large mixing spoon. While mixing the liquid plaster there will be a lot of bubbles.
Tap the side of the mixing bowl with the spoon to get rid of most of the bubbles.
Do not touch the plaster until the plaster has soaked up the water completely and the mound becomes damp.
Mix the plaster mix quickly and evenly with the spoon so that there will be no lumps. You now have liquid plaster. Pour the plaster into your molds before it sets.