Start with the Base
For my layout the base is real dirt that I picked up on a trip to Southern Colorado , near Mashall Pass. I took this dirt, sifted it into different groups and then baked the dirt to kill any seeds that might lay dormant. (This got me a strange look from my wife!)
Once I needed it, I would throw it into a scenery blender (aka cheap coffee grinder) and get the dirt down to a fine dust. I would take this dirt and mix in some smaller rocks to help simulate the high country terrain that I am modeling, where rocks were very prevalent.
I then add in some saw dust (where the trees might be) and a layer of ground up leaves, just to give the base a non-uniform look. You could probably add the dried leaves into the dirt if you would want to, it would be just used to help give the dirt some non-uniform look.
Once you are happy with your first layer, mix 50/50 of Matte Medium and water into a dropper (I used old glue bottles). Make sure to do wet water on your scenery so the glue can soak in. I use 90% isopropol alcohol in a spray bottle for this step (same when putting down my ballast or dirt for the track work).
