When our daughter moved out of the family home in 1987 we found ourselves wondering what to do with the now empty bedroom. Dave proposed building a model railroad in there and my love of miniatures made me willing to participate.
We knew the first question we would have to answer was what scale we would use. We thought N scale would let us have a railroad that felt like more than HO scale would in the same space but we were concerned about being able to work comfortably in the smaller scale. So we bought some N scale equipment and played with it long enough to know we could be comfortable with that size. We also learned that buying more expensive locomotives was worth the cost.
Then we bought wood and made sectional benchwork. We cut one corner off each of four 4' x' 4' pieces of plywood and made sections for each corner of the room. Then we made 2' deep sections the length needed to fill in between the corners.
We designed a railroad to place on that benchwork according to what we'd learned from publications of the day. Thus we had a main line loop, a small yard, and a couple of industries at each town. Then we connected the sections with main lines that made the loop bigger with each town we added. We used block control with powered turnouts on control panels and wired everything for two operators using an MRC power pack.
We built, wired, and operated town 1 on the section right inside the door to the room. Then we built town 2 in the opposite corner of the room. The corner in between was to have a resort on a mountain reached by an old time passenger train going up the mountain on switchbacks and the final corner would have a large city built above hidden staging loops.
But before we got all that built, we got involved with an operating group and decided we wanted to be able to host operating sessions. So we sold the ping-pong table, moved our railroading into the amusement room, and built a bigger railroad. Once it was operational, we sold town 1 as a stand alone railroad to a man buying a great birthday gift for his young son.