Another tip, for making skirts for real people not dressmaker's mannequins:
Create the circle skirt using the hip line instead of the waistline (use the hip circumference instead of the waist circumference, and the distance from hipline to hem)
Measure up the back center line the distance from waist back to hip back (waist_back_to_hip_b),
Measure up the side seam the distance from waist_side_to_hip_side (waist_side_to_hip_side)
Create the arc from waist back to waist side.
Measure up the back center line the distance from waist front to hip front (waist_front_to_hip_f)
Create the arc from waist front to waist side.
Create the details for both front & back circle skirt pieces.
After sewing but prior to hemming, hang the circle skirt for one day from the hip line, not from the waist line. Some leveling may need to be done by chalk marking a level hem while the client is wearing the skirt, but the amount of levelling will be tiny and won't affect the drape.
This way those with:
-big hips don't get a 'hike' in the back
-big tummies don't get a 'hike' in the front
-small hips and tummies don't get a 'hike' on the sides
This skirt will have a beautiful swirl. The adjustments for different lengths in front & back were made during design at the waist, not 'fixed' by adjusting a new hem.