Not sure this is the best forum for this discussion, but here goes.
Over the years, I have read a handful of articles in the hobby press about guys who build their layouts they real railroads build theirs: they build the scenery FIRST and then lay track (modifying where necessary to make it work). I don't just mean painting the plywood prior to laying track: these guys built mountains, streams, forests, Then they hacked at the "rock" and cleared out trees for the grade and then the rails.
Has anyone here approached the project that way?
I can see a certain appeal in the method, but it seems a little wasteful and probably more expensive. Besides: I'd cheat and plan ahead. To do it right, you'd have to have someone else play God and build the terrain . . .