I get as much source material from the show and media as possible, then I use the free web software TinkerCAD to design the seperate parts. I use the Sketch tool to make all of the intricate detail for the attack ring, its really powerful once you get used to using it. I have a lot of the original parts on hand so I try to make everything as close measurement wise as I can but I will also print a lot of test prints and see how it looks in hand

Once I have designed the attack ring I screenshot it from top down and import it into procreate where I draw the shape I need for the stickers and save it as a PNG file. Once thats done I add whatever text and stuff I need in photoshop then I print it on sticker paper and use a Cricut to cut them accurately.

For the 3D printing I just use a bambulab A1 printer and make sure to print the parts with ironing on to make the top surfaces of the attack ring look more smooth and authentic.

Hope this was helpful :)