The scene above is a little service station along the road just beyond the grade crossing. The basic terrain, ground cover and asphalt road were already in place. Here's how I build up the additional detail to complete the scene.
I mask off the pad where the pump island will be, and paint it with Floquil concrete.
Static grass is applied to simulate a weedy, overgrown look.
The building is from Woodland Scenics, the pumps from JL Innovative. Here you can also see the random lines from cracking and settling, that appear over time on older asphalt and concrete - this was done with a #2 pencil, then wiped lightly with a rag to mute the pencil lines.
From there, it's just a matter of adding detail - vehicles, people, fencing, tools, etc.