Growing Moss

I've been told that to prepare the soil surface for growing
moss, spray skim milk from a mister bottle onto the surface.
This also helps if done periodically on the surface of the moss. 
However I haven't tried it personally, although the local 
bonsai nursery proprietor swears by it!

I once saw a childrens science television show  ( Bill Nye the Science Guy) that showed how to make moss by finding some natural moss in the woods, wherever, and then putting it in a blender with some milk and mixing it up and then you can pour it wherever you want it and it will grow in a short time. 

I've found that moss is best when it is collected from 
local areas and placed onto the bonsai container after 
excess dirt has been removed. It also can get rather dry,
this is best avoided by spraying the surface of the 
container lightly with water every day. Also, when storing 
moss it is important not to keep it on top of other moss as
it will begin to grow on to the other moss.

  Actually I'm looking for any tips on encouraging any of
the various mosses to spread.  I'm try to avoid the 
patchwork look of placing pieces of moss on top of
the bonsai container.