The Skirt Skills
class by Brooks Ann Camper may be what you're looking for. The class addresses most of the issues raised in this thread.
Brooks Ann learned to sew without reference to patterns and now teaches her method, resulting in what she calls "you-sized" patterns. One particularly memorable video shows her and her husband side-by-side, both with the same "skirt measurements" if you go by commercial patterns. And you see plainly how ridiculous that is in the video: he is a tall, gangly fellow and she is a tiny thing. But since they have the same waist and hip measurements, they must of course
wear the same size.
An assistant for taking measurements is helpful, but she goes through ways to DIY.
Poochy tummy, uneven hip, flat bottom - whatever figure variation needs to be addressed, it's covered in the class, or can be covered during Office Hours or in the Facebook group.
The skirt class is the foundation to Brooks Ann's other classes: pants and tops. I believe the skirt block is required to enroll in the pants class.
I cannot recommend it highly enough. Registration opens soon, and fills quickly.