I use the Squirrel Valley arrival/departure yard for storing four inactive trains and merely turn on power to any one of these tracks during train arrivals and departures. The consists vary because trains can have just picked up or just dropped off cars. Normally a train that is slated for two switching operations will pick up one car (e.g., a reefer of processed fish) and drop off another (e.g., a boxcar of packaged nuts), keeping the length of the train (when it's in the yard) constant. I have many uncouplers in appropriate places in the yard so that I may vary my operations and do major switching operations like in a classification yard any time I want. See fig. 2.
I use the hidden staging tracks behind the Seymore City backdrop for storing three more inactive trains and power up these tracks only when trains arrive and depart. (See fig. 2.) When one train goes through the portal in the backdrop (and isn't seen again for quite a while) and another one comes out the portal on the other end of the backdrop, the illusion created is that a train has just gone from Seymore to distant points west on a fairly good sized railroad. This denies the reality that the track behind the backdrop simply goes into one side of the backdrop, loops around, and comes out the other. And that's the plan, obviously.