The basic technique is same as the mermaid costume here. So instead of giving you all the steps I'm just listing out the differences. You know, in case you would like to make one of these.
Crochet Elastic waistband ( Small to Medium)
Pink Tulle 6 inch roll 100 yards
White Tulle 6 inches wide 25 yards
1. Instead of tying tulle on one edge of the elastic band, you tie it to both ( yes BOTH) ends. Then you fold the band in half. This is what makes it so full.
2.All the white tulle pieces are tied 5 inches above the ends. No staggering needed for this style of pettiskirt.
3. Cut the tulle pieces twice the length from band to the knee. Ballerina dresses typically stay above the knee so we need to cut shorter tulle strips for this costume.
4. Instead of tying the elastic at only one shoulder, I threaded it through the top edge of crochet band in front and then took both the ends and threaded them at the back. Then I tied them at the center of the back. This will make the dress more snug and comfortable to wear.
5. Take out the stem and stalk of some fake flowers and layer them on top of each other. Hand-sew these flowers on the crochet band.