I made two bowls for the bathroom. One for the sink and one for the toilet. I formed them out of paper clay over a teaspoon measuring spoon. I used one of the bowls to make the sink. I also used two straws and a rivet for the drain.
I cut the top and back of the sink out of foam core. Then I cut a hole for the sink to fit in. I finished it all with paper clay.
When it was dry I lightly sanded and painted the sink with white gloss paint.
To make the pipes, I just bent the straws and filled them with vinyl spackling. The bend is used to simulate elbow joints. I ran the water pipes up to the faucets all made of florist's wire.
When the "pipes" were dry, I painted them with silver alcohol paints. I added little faucets and I added a little drain plug, then fastened it on with a chain.