Since the game is not out yet there's a limited number of reference photos, so I have actually no idea on what the dress looks like from behind.
As I am not the best seamstress I started with the necklace ;)
(gimme that worbla)
Here is a rough sketch of the patterns for the worbla (sorry, I have a tendency to scrap the real patterns when I'm done)
1. is the larger base of the necklace and 2. is the ornaments on top of that. 3. is the collar going up to the neck and 4. is just a strip of worbla used to hide the seam between the lower and upper part of the necklace. 5. is the ornament hanging, here I first made a template in vardbord, build it up a bit with paper clay and then covered it in worbla.
I used my tailor bust as a model, covered in tin foil so the layers of worbla would not get stuck. Here I am adding the upper collar (part 3.)
I have only used one layer of worbla here, but I would recommend a double layer as that won't get so "wobbly".
A lot of adjusting to get the shape right with several test fits on my own neck.
Primed with Gesso
More layers of Gesso
And detailed using dark brown acryllic paint, first a weathering coat and then hand painted details.
Some more detailing
Finish off a clear coat.
Here I have trimmed the edges, you should do this before you paint (but I forgot).
(It is hard to smile AND take a "selfie" apparently)
This is the result, I might add more details laterbecause I am not pleased with the colored stone, but now I have to finish the corset.
But she also have a bracelet
So with my worbla leftovers I shaped the bracelet around a soda can.
Primed with glue and painted gold.