I've seen people use nuts(as in nuts and bolts, not the food) in their dreads. I don't really decorate my dreads, I probably would use skull beads if I could find any that looked really cool. Like the mardi gras style skulls.
strung hemp through a dread, then macrame and braided the hemp and put in colorful beads. then i have also bent beer caps in half on the hemp to secure them. :) i personaly loved this, cus each diffrent cap was a diffrent memory:) i have also done wraps too.