Things You'll Need
Instructions
Decide upon a track plan that you can afford and have room for. Take into account accessibility of switches, ease of operation and other prototypical factors. Make up an itemized list of all of the track, structures and other equipment that you need, and start shopping. Look online or browse at local swap meets, where you can often find good deals.
Begin constructing the bench work to fit your track plan. There is no one right way to do this; you may just need to make a table with legs of the necessary size, or you may have to cut and fit many different pieces of lumber to create a more complex array of overlapping tracks.
Begin laying track after the bench work is done. Lay the track in parts, testing the track with an engine and cars before you finish so that you can spot errors more easily. Make sure that there are no kinks in the track work and that the tracks don't curve too sharply for the trains to run over them. Drill holes for under-the-table switch machines if you are going to use them.
Start wiring the layout after all track has been laid. You can either wire the layout in blocks or use a command control system if you can afford it (this is much easier). As with the track work, wire the layout in sections to test for errors. Then, conduct several operating sessions to ensure that your trains run correctly in all directions.
Assemble and place all of your structures on the layout next. Drill holes in the bench work for lighting wires if you are going to put lights in your buildings. Insert the bulbs and wires into the structures now for convenience's sake. Paint them with flat black paint to diffuse the light and make it more realistic. Mark on the layout with a pencil outline where each structure goes. Then remove the buildings before applying scenery.
Apply the scenery last. Coat your bench work with some kind of sealant, then apply an earth-colored paint over it, leaving bare the spaces outlined where your structures go. Then shake a mixture of scenic lichen or foam onto the wet paint to simulate foliage or grass. Use plaster-of-paris to create mountains or hills. Weather your trains and structures with paints or chalks to make them look real.