Good luck! Great to hear about other Morrigan cosplayers
I think I have some progress pics if you want to see how I did the bulby part of mine, right here and here.
As for the planky part of the necklace, I sewed a shirt collar out of scrap cotton, but left it open at the back and used velcro to close it. Then, I cut and shrank shrinky-dinks, took an exacto knife to the edges to bevel them (carefully and painstakingly T_T) and glued 'em to the collar. Lastly I spraypainted the whole thing with gold chrome spray paint and sealed it so it wouldn't flake ^_^