The last part of my new underwear is a rather basic skirt made from dark grey cotton (unfortunately I had not enough left from the fabric I used for the shirt and unmentionables) and some black lace. I used the Burda Crinoline pattern and shortened the skirt a bit - I don't want it to peak under the actual skirt!
Unlike the shirt and underpants, this basic under skirt is really a necessity. You need quite a bit of fabric to keep the actual skirt tamed while walking or when it is windy. The underskirt really helps with keeping the form you planned your skirt in.