Pattern might not have been a bad idea. I did one for my helmet using some black vinyl and just kinda made it on the fly. Did it in 4 pieces, with some seams that will be hidden by the interior padding/MS kit. I cut out pieces for the back/sides, the top section and forehead, and the mandibles. All in all it was fairly easy, and the only piece I had to redo was the top section, all attached with hot glue.