As usual patrons see it first!
This is how I made my Sailor Senshi skirts.
It's a super easy method that's great for adding proportion to your costume for designs that don't allow for a petticoat.
You'll notice that mine ends up being like a wavy gathered skirt (I was aiming for the Manga version look). If you want to make the anime version, simply pin each fold along the entire length of the skirt, and iron the folds before sewing. This will make the pleats.
Feel free to ask questions <3