While I realize not every costume can be best created out of cardboard, I wanted to inspire you with a little idea for some covert cardboard.
At one point I tried to construct a full blown petticoat out of cardboard, but after more than one failure, I thought there must be a better way.....
Surely this is a trick that every mother should have up their sleeve? A kind of Julie Andrews move akin to pulling the drapes off the wall and stitching up a dress, except you'll pull a strip of cardboard out of your recycling and make an ever-puffy twirly skirt.....hopefully while singing?
Just staples and a long strip of cardboard is all you need. Make sure that the corrugations in the cardboard run parallel to the skirt's hem and you'll get a smoother contour.