For me there is a Rule of Social Logic. That is people need things and do things. Just a bunch of house and a factory looks silly. No matter how you dress them up there is no social logic. That is why when you look at some routes there seems to be something missing. You just are not comfortable with what you see. There is a parking fare filled with nice hi-res well painted cars but your mind also wants a gas station. Lots of houses but some people may wonder where do they get their groceries, fast food, the bank, etc. So, unless a town/village or city is socially balanced there may be that "something is missing" trigger in the viewers mind.
If the town is not a stop then some familiar fast food or gas stations might be sufficient to give a "real town look". But if it is a stop those items essential to modern life need to be represented.
Yes. I agree with this approach. When I work on a route, I get myself to the trackside in Surveyor and have a look around as if to see the area from a resident's point of view. If I'm building a town, I'll go to my usual assets I use for that and start building. In my area we have the bigger, fancier houses on the outskirts with the less fancy houses towards the downtown. As we get close to the town center, we then have the usual bank, bar rooms, gas station, merchants, police, and fire station all laid out around a town square.
I will sometimes look at maps and street views to get a decent view of what these look like and even if the place I'm looking at isn't the area I'm modeling, it gives the general feeling for the area.
Here's a couple of cities and towns I have referred to in the past.
Andover, MA
https://goo.gl/maps/NXVRDwkd9Fx looking south on Main Street.
https://goo.gl/maps/A6v85c9cbTU2 a bit more downtown.
https://goo.gl/maps/zasU6R3ZND92 Corner of Chestnut and Main.
Hint: I used to live here so I know the layout pretty well too.
In this case, the railroad is nowhere to be found being some distance to the left down the hill, but that doesn't mean we can't put a Front Street or Railroad Avenue parallel to Main Street with a view of the tracks, or put the station on Main Street where some of the buildings are to change things up a bit.
And for an interesting town layout built to serve the local coal companies and parallel railroad (Reading and Northern), take a look at Mahanoy City, PA
https://goo.gl/maps/Q19s5MMzEZK2
The parallel layout is perfect. The town its self is very shallow compared to others and there's nothing but hills and trees behind it today. In the past, however, this area was covered with various anthracite coal mines and a lot more railroad tracks.
https://goo.gl/maps/5REypJSppCJ2 - A view of the downtown and the parallel railroad, where railroad street runs along the railroad. There were once small rail-served industries here. Model as you see fit.
Keep in mind too we mostly see only the backs of the buildings and gardens rather than the pretty fronts, and there's a lot more overgrowth and trash along the tracks than there is on the streets.