The design of the dress followed the fiber optics that it needed to support. As there is one central light source, I designed the back to include a pouch for the handle, and the straps of the dress to bring the fiber optics from the center back to the front, and back around the body to an even distribution at the hips.
A big design challenge was how to give the filaments enough lift at the skirt, as I wanted the skirt to push them out at as near to a 90 degree angle as possible. I was considering things like a fully boned structure or 3D printing small pieces for each group of filaments to angle them out at a perfect right angle. However in the end I just went low tech and stuffed the skirt with tutus :) I'd still like to explore these other two options eventually.
Be warned that this Instructable includes a major fail at one point, so read the whole thing first if you intend to make this. I ended up designing the dress and fiber optic design in different parts of my mind, and put the zipper on the side not thinking about the fact that once the fiber optics were sewn down, I couldn't open it! What I was thinking, I have no idea (I wasn't). But as recovering from major errors is an integral part of making, I included this saga in the Instructable.
I chose to make this dress from scratch to dust off my fashion skills, but you could definitely make something very similar by buying a V-neck dress with a circle skirt and skipping to step 13.