Thanks to those of you who have asked if I am still trying to do the knock-off of this dress:
The answer is YES, but I had to take some time off to think about how I want to proceed to get that middle blue piece to have the crescent-shaped drape like the above image. I have studied patterns that have sort of the right look, and the new Threads magazine even had an article about making a hip drape which helped.
After much thought I decided to re-cut that middle pattern piece. Instead of curving around to fit the other pieces (like the dark line), I just cut it straight from the top (like the green dotted lines).
Now I just need to re-cut the pattern so it will have the same proportions as the inspiration design. Maybe I'll do one more "test model" before cutting out the REAL fabric. I need to get to work if I'm going to enter it into the Pattern Review Knock-off Contest as it ends next week! More later.