I didn't capture the process, but we made a mold with a gelatin/ rubber-like material to mold the foot, then poured the plaster into the mold. When the plaster hardens the rubbery mold is then peeled away and you end up with your object. It took a few tries, but eventually we got one we were happy with.
A few small bubbles got trapped.
And now just a little over one year later, at 17 months old. She still curls her toes like that sometimes.
We also stamped her foot into a dish of the plaster. This was our best result with such squirmy feet.
