We have only a small area in the back yard for a garden railroad: basically about 8′ by 32′. Robin and I did a detailed survey of the space so we would have an accurate idea where things were: sprinkler heads, fences, trees and other unmovable objects.
I then used 3rd PlanIt to design the layout. It was very easy to recreate the Aristocraft sectional track in 3rd PlanIt and duplicate as many times as needed. I played around with a lot of different ideas before settling on the following. It’s very simple but scenic at the east (“top”) end. The ruling diameter with the curves is 5 feet (2.5 foot radius) so the layout is for small engines and rolling stock only.
The other big feature was building elevation changes into the design. This appears to be a no-no for live steam engines, but my preliminary tests indicate that the 1.2% grade I planned should cause no major problems. And the layout definitely looks better with the vertical separation between the front and back.
While building the layout, I decided to add a bridge at each end to drain the loops. They add visual interest as well.