How do I poof my elf skirt?

Last winter I sewed an elf costume to wear during my holiday busking. It did a fine job, but this year I’d like it to match the image I had for it, where the skirt was a little poofy. I tried putting a tulle tutu under it, but it just bunched it up. It’s velvety with a fake fur trim. Here’s what it looks like now (and side view).

Will it be possible with this design? Anything I can put under it?

Thanks!