I have two 4x8 sheets of 3/4" plywood that come down via pulleys+cables+motors from my garage ceiling.
Sheet one is a classic figure eight with the good-old plastic trestle set, and has a bunch (4) of those old "activated action scene" track modules around the flat areas. It is a fully painted surface (green "grassy" areas and a brown strip of "road" going across the board and thru the two electronic gate sections) with raised cork bedding. There are no permanent features that are not part of the track.
We used to put our Christmas tree base in one side of the "eight" and stack the presents in the other, but now it's "just a track section."
Sheet two is a dual oval with a couple of small switch yards in the middle area. I fully intended to turn it into my first full-blown diorama piece, but never made the time to do so.
Hence this sheet remains a pleasant "woody" tone.
Track is tacked directly to board w/o bedding.
Each board has a pair of switched sections that allow them to be linked together, side-by-side, and run as a full, HO setup. (All the switch controls, however are mounted under & on sheet two, so you have to run things from there when they're linked.)
FYI: My wifey loves trains even more than I do, so I have NO PROBLEM-O spending time on these things... so long as SHE can play with them too! (I.e.
I do all the work, but....
)