Currently one of the works I'm making for the fmp project centres on having a tea set with a Chinese atmosphere to match with the illustrations. The photo below is my plaster cast of a small teacup I made during ceramics. The process to making a plaster cast is having a box shape that can fit in what is wanted. Rolling out a slab of clay that will fit neatly into the bottom of the box where the top of the cup get pressed into and brushing on oil in the inside of the box and the object so it all slides out afterwards. The brush will need to cleaned well after oil or it will be unusable. Generally its good to have another box roughly the same size as the other instead of using perhaps a bucket, as you'll need to be a good judge of measuring the amount needed otherwise. So with the other container judge a halfway point of how much cold water will go in and then scoop up the gypsum plaster and sprinkle it over the water in the container quickly. It needs to be consistent by taking care not favour any areas while shaking it over. When there's half of the powder and water stir them together to have a liquid cake like mixture, a way of telling a half way point has been reached is if there are 'islands' all over the water. Pour all the mixture in and then lift up down that container to get out the air bubbles. Any remaining mixture should be thrown in the bin and the containers should be given a second bath in a bucket at the sink to avoid clogging the pipes.