Although I picked Hufflepuff, it doesn't mean you have to. Here's the houses and the corresponding colors...Gryffindor: Scarlet and GoldHufflepuff: Yellow and BlackRavenclaw: Blue and Bronze (the Bronze ...
I like to call this part the mini skirt. You will need three measurements for this.
1. The measurement you already collected previously for your hips
2. Where on your waist you want the top of the skirt to be
3. The length from the top to the bottom.
See the diagram below for how to cut the mini skirt out. (Cut out two identical pieces)
After the skirt is cut, pin the pieces together (with the top folded down). Sew the top hem flat and then sew up one side of the skirt. The other side will be left disconnected, but sew hems on those to make it look nice.
When all the sewing is done, the skirt should kind of look like the second picture.