As far as waistlines - is the person's waistline parallel with the floor?
Mine isn't - and it is not a commonly shown alteration - it is about three inches lower in front than in the back - so a skirt clinging to the narrow part of my midsection will really droop in front.
Pants are usually really short in the center back and come up almost to my breasts in front. (I did try turning them backwards - but that didn't take care of the problem, either.
)