Hey Don, I see my old Lionel station behind those passenger cars. Happy to see it still has a very good home! I would never have room for that now on my current layout.
Don, you well know that I have gone the hi-rail approach in the past with scenery. For this last and current layout, I went with what I jokingly call a "low-rail" approach.
I painted the whole board a satin grey for the track ballast. Then I put down all the track, made sure everything worked, then added brown foam ties that I cut myself from those foam sheets sold at Hobby Lobby, Michaels, etc. to reduce noise rumble to an acceptable volume.
From there, I used a light green paint to generally paint every area that wasn't the "track ballast." At the craft stores or even Walmart, you can buy these small containers of acrylic paint in all sorts of colors for 50 cents to one dollar. I used all different shades of green, brown etc. And as time allows and as the layout developed, I would add different shades of green and brown over the base coat of green to mimic more actual detail.
Around a work building or a water tower, you could add more brown to mimic less grass and more dirt or mud. Around a station or a diner, which would naturally have a more manicured lawn, I keep the green more uniform in tone. Roads are easy by using black or very dark grey. Or dirt roads by using various shades of brown.
And if you don't like what you did, it's easy enough to paint over it and change it.
I'm still making hills and mountains out of blue or pink insulation board. Latex and acrylic paints work on these just fine.
Yeah, even being an 027 guy, I always liked the hi-rail approach to scenery. This time I wanted something that was easier and lower maintenance. And it just happens to have a more postwar look to it also.