Methyl Hydrate (isopropyl alchohol) is available in gallon jugs at your local building supply store in the paint department. Cost is about $5.00.
In one spray bottle, I mix up a 10% solution of matte medium, methyl hydrate, and a couple of drops of liquid dish soap. In another spray bottle, I fill another spray bottle with methyl hydrate.
I mix up my scenicking materials, whether it's ballast or ground foam in small cardboard or styrofoam coffee cups. When applying the materials, hold the coffee cup in one hand and tap the back of your hand with a 1" paint brush. This controls the placement and distribution of the materials.
Don't try to apply all of the scenicking material in one go. It's a layering process. I layer on the scenicking material (whether it's ballast, ground foam, etc), brush the ballast into place with a 1" brush. When I'm satisfied with the look, I mist the material with the matte medium mixture. Then I mist the matte medium and the scenery with straight methyl hydrate until it is almost flooded. Let it dry for 24 hours.
The next day, apply the next layer of scenicking material and repeat the process.
Keep the matte medium out of the points of the turnouts. It's very easy to cover the points and any other sensitive work with cardboard "tents" made out of index cards folded in half. If the turnouts do stick, spray with methyl hydrate, let it sit for 5 minutes, and then clean out both sides of the points with a Q-tip. The matte medium is also on the ties that the points slide on. This may require several applications of methy hydrate and Q-tips
The idea here is to layer on your scenicking materials going from fine to coarse and saving the ballasting to last. In the same way that an artist stands back from their easel to see what they have created, frequently stand back and try to visualize the look that you want to create on the piece of layout you are creating.
Don't rush things. You have lots of time. Take photos of the kind of scenes you would like to create using nature as your model - rock outcroppings, trees, fields, grass, etc. The idea here is to try and mimic the colours. Frequently we use scenicking materials that are too dark (eg dark greens), too solid (dark green covers the whole area. A small piece of nature is a kaleidescope of colours - different greens, different yellows, hints of orange and red. As my sense of colours isn't good, I get my artist wife to mix up the greens for me - lots of medium green, a hint of dark green, and a bit more of light green. Fine foam first, followed by medium ground foam, followed by clumps of coarse foam strategically placed. Leave a bit of the ground uncovered on the sides of embankments (painted light grey with drybrushed streaks of dark grey, light brown and dark brown).
The end result is really tremendous!
Bob M.