Hi everyone.
Thanks Davie_UCF & Ray_Whiley for your kind words.
Your encouraging comments, and progress on your (Davie’s) route, have prompted me to post a couple more ideas which have worked for me.
I see you now have a couple of sidings. One in use through the shed; the other disused.
The live line has shiny track: the dead one is rusty. That’s great, but you can add further to the realism.
The live line end probably needs buffers of some sort. The dead line probably doesn’t matter too much.
I use transition pieces of track which, although subtle, help greatly with realism.
Buffers at the end of a working line.
Your loco or rolling stock will never keep the track shiny beyond the point at which the buffers do their work to stop the loco/truck/carriage. Placing an item of rolling stock against the buffers in Surveyor will show the point at which the rails will never be kept shiny by wear and tear. In reality this is a gradual, not an abrupt change in rail type. This is where the transition pieces come in. I mainly use ‘drstrach’s stuff (>100 track choices!), but there are others available including UK bullhead which I also use, but with less choice. The following two shots show the UK bullhead type.
In the first shot the lower of the three tracks is the transition piece, (deliberately stretched to double its useful length to better illustrate the way it works). In practice you obviously just use half to make the transition.  
kuid:179051:102000 is the transition piece from rusty to shiny. All rusty is 101999. All shiny is 100459. 
Simply butt joining the two contrasting rail surfaces together is not a good look (middle track). 
Using the transition piece gives a subtle, but more realistic look (top track with buffers).
		
		
	
	
Adding a bit of greenery and perhaps a bit of identifiable domestic stuff like a garbage bag or supermarket trolley will help with upscaling the railway hardware to make it look more like its actual size, and therefore a bit more realistic.
Derelict lines
With these you can go from rusty, then to sleepers only and then to faint marks in the landscape where the track used to be. No buffers required unless you want them - and great scope for some overgrown areas with rubbish/wild flowers etc. Here I’ve used ‘drstrach’s tracks:
 
Apologies if you already know all this, but someone might find it useful.
Cheers
Casper
