A very simple way to make a papier-mâché bowl that I absolutely love from Anthea Carboni at Yuniko Studio Blog
1 cardboard egg carton
bucket of water
Hand held blender
wire sieve (around 15cm diameter)
sponge (10 cm round is ideal)
Tear the egg carton into small pieces and leave in a bucket of water (1/3 full) for a day or two. Use the blender to make a pulp. When the mixture is an even, soupy consistency, hold the sieve over the bowl and pour enough of the mixture (slowly) into the sieve to fill to the brim. Rest the sieve over the bowl and wait for the water to drain, taking care not to move the pulp around.
Then use the sponge to gently press the pulp against the sides of the sieve, starting at the bottom and then working around the sides, lifting the sponge up gently each time. Squeeze out the excess water from the sponge as you do this.
When you have removed most of the water, turn the sieve upside down and gently tap the sieve against your other hand to release the bowl.Reshape the edges if needed.
Dry off the bowl in a cool oven (defrost setting or around 80 degrees centigrade)for about an hour.
One egg carton makes around 5-6 bowls. Most egg cartons are grey (the one in the photo above was a surprising blue and the one below a pumpkin yellow) but you could easily colour the pulp by adding food colour or edicol dye (food-safe powder colour)