I made this for a coworker heading to Disneyland for Halloween! Wish I was going.
It's a circle skirt with an elastic waistband, knee-length. I did the maths for the pattern; I had to look it up because my teachers were wrong: I don't use this stuff on a daily basis.
On the tulle I just kinda winged it.
I used 2" wide non-roll elastic and made the casing 4" wide with 1/2" seams so she wouldn't need a zipper or hook and eye closure. And I wouldn't end up stuffing the elastic in and swearing at the casing because I made it too small. *cough*
I serged the seams and rolled the hem. No unfinished stuff here. I reserve that for my own wardrobe.
The tulle petticoat I gathered and stitched onto elastic so it's removable (Although anyone that doesn't want a poofy skirt is suspicious in my book).
I thought about adding bias tape or ribbon to the bottom of the tulle but decided against it. She might want to use it for something else some day.
Disclaimer: I am not as small around as the dummy. I wish! Although yeah, my top *ahem* is bigger than that. Also maybe not quite so lopsided.