I've used some sculpey translucent resin type clay that you bake in the oven its goes rock hard like plastic and not like soft clay. I used a pole to sculpt them on and each one gonna turn out slightly different. Or you can make a few and cast them. Although I couldn't tell you how to cast buddy I'm sure there's more fellow hunters on here that can.
There's is a million and one ways of doing it and none of them are wrong. I do think thats the joy of making em yourself. Each Pred can also be an individual, shape colour and size and have untold types of customisation done to it.
I used a few different methods for my dread rings.
The simplest rings I have were made by taking two of the "skull drinking funnels" that I got at Halloween, and cutting the "spine" into sections for dread rings:
I also have a set that I made by using 3d fabric paint to make designs on some PVC couplings that I got at Home Depot and painting them:
And then I have three different sets that I cast in resin. I made the models from short sections of PVC pipe and put designs on them with two-sided taspe, then molded them in silicone rubber and cast as many pieces as I needed. The set pictured here has a "facehugger" motif:
All of these methods worked well and gave pretty good results. So it's just a matter of how much time, effort and money you want to spend.