I have a group of drier balls ready for the upcoming Farmers' Market. I thought you'd like to see them before and after final felting.
Here they are ready (or almost ready...note the color of the bird's beak) for final felting:
Then they get stuffed into an old stocking or two. I use twisty ties between drier balls to keep them separate.
The balls get soaked in a bucket of water, squeezed to get some water out, and then they go through a cycle in the clothes washer and the drier. After that, I do a little bit of touch-up needle felting and they are ready to pair together and use.