Hi Dontano,
usually a good coat of paint colored in the earth tone of the region where the railroad is located. Then, white glue and scenic material finish the job.
If you want to mimic Lionel's postwar display look, it is all paint with some of their mixed color grass glued on. There are specific colors for that look.
Back to earth tone - if you go outside and look you will see that there is earth showing through everywhere there is vegetation. So, one doesn't completely cover an area with grass or shrub material. it is all a blend that the eye sees as one texture.
Even the earth tone changes color depending on the region. (topsoil, clay, sand, rocks) So, two or three colors are slopped on as the base coat.
yeah sounds like modeling, but it is easier than you imagine.
Roads and streets can be taped off and painted with clean lines.
I think Woodland scenic still has "grass paper" but it is on vinyl backing and can be shaped. You can get a lot of scenic material and paint for what they cost.
There are many videos on youtube on creating scenery.
Just back up a few levels from what you consider modeling and just slop on the paint and haphazardly brush around glue and sprinkle scenic materials. You'll get a better effect than a mat and like the look compared to just paint.
