So I decided to make my barricades look better and came up with a fairly simple solution. I also added some of my finished Snowtroopers (although somewhat confused about their ecological surroundings...).

Spray prime grey, dry brush in Army Painter's "Dry Rust"

Washed in a dark tone

Dry brush again in either Army Painter's "Ash Grey" or any other slate grey color

Finish with a light dry brush of "Gun Metal"

I added an image of the simple primed barricades for perspective. Simple solution, relatively easy. Thanks to @Sorastro for all of the videos I watched. I may not yet be up to par with 90% of the techniques, but I feel as if I am actually picking up dry brushing a little bit better. Finally feeling like taking some risks and stepping out to produce something on my own. Feels pretty good.

Nice looking work.

Regarding "snow"troopers, I've started to think of them, not as having any ecological niche in particular, but, given that they have skirted uniforms not unlike the Clone Wars era ARC Troopers, that these are a specialized assault force that are pretty much the Imperial Stormtrooper Corps equivalent of ARC Troopers. Saves me a lot of mental stress wondering where all the snow is... (my terrain theme is definitely desert.)