So yes, I am making a Symmetra cosplay and with the release of the Peacock skin my choice was easy. I am also in luck as Kamui has made this costume before and has published a tutorial. Check it out more more information.
The Head piece
This fabric is not stretchy at all, so I added several darts to make it form fitting (sorry that some of the photos are screenshots from IG) The patterns are heat transfer vinyl.
The details on the chest are sculpted, molded in silicone and casted in resin.
To get the oil slick iridescent paint that matches the fabric I used three different metallic spray paints.
I sewed the top in a skin colored spandex, so the leggings wouldn't slip down. The golden part is sewed from a less stretchable pleather, so I added a zipper in the back and made them as a separate part.
And this amazing photo is by Rojano Photo.