Measure first
Measure the available area carefully and include doors, windows, furniture, utilities, and walking space. Leave room to reach every section of track.
4×8 layouts
The classic 4×8-foot HO layout allows continuous running and can be approached from several sides, but it consumes more room than its footprint suggests because you need aisle space around it.
Shelf layouts
A shelf layout can run along one or more walls and is excellent for switching, realistic scenes, and smaller rooms. It can also grow in stages.
Around-the-wall layouts
Using the room perimeter can produce longer mainline runs and broad scenes while keeping the center of the room open.
Design for reliability
Avoid curves that are tighter than your equipment can comfortably handle. Keep grades modest, provide adequate turnout access, and test the plan before making scenery permanent.
Give Every Train a Reason to Move
Industries, passenger stations, yards, engine facilities and interchange tracks create destinations. Even a small railroad becomes more interesting when cars have places to go.
Keep critical track within comfortable reach. Hidden track, turnouts and electrical connections eventually need maintenance.