Yet as simple as the requirements were, I did not have any long black "bottoms" other than jeans or worn-out yoga pants with holes. So what's a girl to do? As my closet and the Internet had nothing to show for themselves, it was clearly time to hit Jo-Ann Fabrics.
I bought (too many) materials for a maxi-skirt for less than $20. (What I bought: 2 yds polyester jersey, elastic, black thread. What I used: 1.5 yds jersey, black thread.)
As I didn't bring my sewing machine, I decided to do the sewing by hand (with an applique needle!) This may sound like a lot of extra work, but after making my prom dress with similar fabric and having to hand-baste every seam anyway, it is possible that doing it by hand even saved time.
The entire process took about four podcasts of This American Life out of my four-day fall break. It was a terrific way to recharge. I referred to this tutorial for inspiration and direction.