Taking in the waist/hip of green jeans
What I did:
The client who had me take in the waist of her red jeans had bought a second pair of jeans, pale green with a raised flower design, at the thrift store. These jeans were even larger on her than the red jeans.
My client suggested that we make the waist even smaller, so that the pants would sit above the natural waist. This fit would make use of the very long rise and prevent the droopy crotch problem.
It worked! I took the excess fabric in on the back center seam. I had to take off the center belt loop, then sew the seam an inch further in at the waist and taper it down to nothing, then sew the belt loop back on.