Hi all, my daughter loves going to comic cons/cosplays, and has asked me to make a costume for her (Google: "hazbin hotel Rosie" to see an example). The bottom half is a floor length pencil skirt that flares at the bottom, so I've bought a cheap 3/4 length jersey pencil skirt, and my plan is to make the flared part myself and sew it to the bottom.
At the risk of sounding very naive, I was going to cut the two halves of fabric in a "volcano" shaped pattern, with the top matching the width of the pencil skirt and the bottom being whatever width I want the flare to be. I suspect this will be too simplistic though, so I'm looking for suggestions here.
Also, how can I maintain some semblance of shape, rather than the fabric just falling straight down? I'm assuming the flare is formed using a combination of fabric type and a more elaborate pattern than what I had in mind?
The shape doesn't need to be too elaborate or particularly accurate to the pictures (if you've googled those), but any help welcomed! TIA.