The materials I used to make this decorative balls are:
- a newspaper,
- and of course paint and varnish.
I make a hardball out of the newspapers and add som tape to keep it shaped. Then I added one or two layers with pieces of papers and glue like paper mache. Then, I added small pieces of eggshells and fixed them with glue. Instead of eggshells, you can add a layer of paper macheé clay. Tutorial at my blog.