Firstly, I’d go for an 8 panel skirt so that the waist, the full circle effect and the tapering to the kneed gets evenly distributed around the width of the skirt and then I’d curve the outer edges of each panel - something like this:
You will be able to do 4 back panels that are narrow and 4 wider front panels (to accommodate the tum) 
and if you use the same formulas in the curve handles for each panel, they should turn out to be the same length, as well.