Attaching moss to wood ideas

use a flexible mesh or netting that's dense enough to hold the moss in place but holes are large enough for the moss to grow through. then wrap it around the wood or tie in place with string.

I'm wondering if a hairnet or a piece of it would do.

I have also seen people use those plastic mesh shower scrubs (not sure what they are called but my wife has one) that you put liquid soap on and wash with. You take it apart and cut out a section. Nice tight mesh.

http://www.aquariaplants.com/plantingtips.htm

This works with riccia, java moss or any of the other mosses. I've also seen people do this but stand it vertical for a moss wall.