To make the Dalek "grill" on top I got black felt. I thought the adhesive kind would make things easier, but it didn't really. I cut the felt to the size I needed and sewed the corners.
I have yet to make the headpiece. I intended to use tiny dixie cups, blue acrylic paint, and blue yarn to attach the cups to the headband. And there you have it, your plot to exterminate all humans is that much closer to becoming reality.