Snow stacking effect on the terrain

Hi,
I am about to install ETM, and I haven't used it before at all... I would like it to help me generate the snow stacking effect.
However, I don't really know where to start....
Could anyone give me some clue of the steps that I need to implement?
Many thanks!

Well I am still trying to get this thing working myself under Linux. However from looking at the API, this supports real time terrain deformation and splatting. So, have the snow texture as one of your six textures. If you have the x,y,z position of where your snow flake fell, apply a small brush size with a low/medium strength to the point at which it fell. After enough fell, the snow would build up. This wouldn't make 3D snow, but the texture would change. Hope that helps.