Talking of small model railways (real), my smallest was a loco shed diorama in a shoe box - which I had the temerity to take to a meeting of the local model engineering society. And they liked my scratch-built N scale coaches, which I took there in toothpaste tube boxes. Most members modelled in rather larger scales …
The master of small layouts in the USA is (or maybe was) Carl Arendt who has published books and DVDs or CDs with many ideas.
Ray
(Copied from the wrong thread where I first posted this).