A Red Arrow Lines kit is made for the builder who wants to slow down and make choices along the way. The box gives you the structure and illustrated instructions. Your work gives it the finish that makes it belong on your railroad. That can be as simple as choosing a paint scheme that suits your town, or as involved as creating faded signs, roof repairs, window shades, and a service alley.
Start by reading through the instructions and separating the main walls, roof pieces, trim, windows, and detail parts. Dry-fitting the major walls before glue touches the bench lets you understand the building's footprint and decide which side will face the aisle. It is also the best time to think about interior lighting, access to wiring, and whether the structure needs a base or sidewalk.
Paint and weather individual assemblies where it will save you trouble later. A little variation in brick, trim, and roof color often does more than heavy weathering applied at the end. Keep the building's role in mind. A busy cafe may have cleaner front windows than its delivery door. A garage may show more wear near the doors and roof edge. A boarding house may have a mix of curtains, shades, and darker rooms.
Then place the finished structure back in its setting and let the scene tell you what it needs next. A curb, a few steps, a sign, or a small patch of gravel can be enough. The goal is not to add every possible detail. It is to make each choice look as if it belongs there.