I've copied this post about my layout across from the "2-rail home layouts?" Thread as it kind of fits both...
Here's a plan of my 17ft x 8ft layout (not to scale). It's just a single oval, with a siding and diverging branch on one side, which leads round to some industrial spurs behind the 'main' on the other side. There is no hidden staging, "inbound" trains are just staged on the main in front of the spurs, and run round the oval a bit to rack up some miles, maybe while outbound cars are collected from the spurs & brought round to the interchange yard - just the siding & main in reality, but 'yard' sounds grander!!!
The two main types of operation it's designed for is interchange of trains between a Class 1 & my freelance Short Line on the one side, and then switching cars on the spurs the other side. These ops can easily take an hour or two to complete, or I can just run stuff roundy-roundy if I feel like it.
It's actually comparable in proportion to a 'sacred sheet' 8ft x 4ft layout in HO, but I was determined not to overfill it with track. All the track was hand spiked, & switches mostly use Right-O-Way parts, apart from the curved switch frog and two representations of Self-guarding frogs on the industry spurs that I made myself.
It took a couple of years to complete the spiking. I did it in stages so I always had chance to run something during construction. I started with the spurs, worked round to the switch with the main, laid the main in both directions around the room to meet on the other side, and included the switches for the siding, which was laid last of all. Most of it has been ballasted now, but scenic work & plenty of weeds on the 'bad' tracks are still in progress.
Hope that's of interest to everyone.