I am in love with this.
It turned out way better than I could have hoped.
It was inspired by this tutorial at moda bake shop, but I did it my own way and changed a few things.
I got this Jelly-roll at walmart and I think it's just darling. I decided alternating darks and lights would be best for this style of pleating; I really wanted the pleats to stand out.
I sewed all the strips together first, to create one continuous skirt panel instead of several, and pressed to the lighter side. Then I top-stitched on the light side of the seam, to serve two purposes: to contain the inside unfinished seam, and to add further detail to the pleats. I'm so glad I took the extra time to do this. I think it really adds to the skirt.
Then you just fold your dark strips in half and press to create the crease you'll use as your pleat guide, and fold in the light strips to create the pleats. Press and pin, then just stitch all the way along the top of the skirt to set the pleats in place.
After cutting off the sewn jelly rolls at the crease in the middle of them (they're 40" long - too long for a child's skirt), I gave it a big fat hem (and it's still long) and used some of the scraps to create the elastic casing. You may want to do your measuring first so you know how far down the strips to do your sewing and top-stitching.
So really, I could do the whole thing again with the other half, but I think I'll save it for quilting.
I mean, isn't she precious!?!