I started off with a paper mock up of the armor to see what the shapes were like and got them as near as I could to what I saw in the cinematics. There was a lot of trial and error here as I was making all the templates myself. Then I transferred them onto styrene sheets and glued thin foam onto the back to give it a bit of thickness and cut them out and hot-glued all the seams to make them 3-dimensional. All the embossed areas were basically the same shapes cut out of thinner styrene with holes cut out as well as thicker foam for the raised areas as well as twisted rope for extra detail around all the edges. After that I covered EVERYTHING in Gesso to give it a nice surface to paint and sanded it all smooth so when it was spray painted it would be nice and shiny. Then came the spray paint, probably a couple of coats just so that everything was evenly covered and when that was dry I rubbed over it using an old rag with heavily watered down burnt sienna acrylic to antique it a bit so it wasn't so 'new' looking. The 'skirt' was much the same process. Templates first then transfer them to leatherette, stuck on some cream leatherette for detail and finished with a gold 3D paint. Then all of it was precariously held on me with lots and lots of velcro
There were a few other bits here and there but that's the basic process I used, hope it helps ^^
Thanks a bunch for replying. A friend of mine is doing a Ganon cosplay and your armor looked pretty sweet, so I thought I might be able to apply your process to his armor. This was def a help. Thanks again.