It was easy-peasy to prepare. I just followed the instructions on the bucket, using very cold water.
This is the consistency we used.
We quickly poured the plaster into our molds. We found some aluminum pans in the cupboard that worked pretty well. The plaster was initially too wet to hold the weight of the beads and decorations, but after we let it sit in the molds for five minutes or so, we were able to press our embellishments right into the thickened plaster.
We may paint or color them someday, but until then these paperweights are doing their job decorating/holding down papers on my kids' desks.
Hope this brings someone else enjoyment too!