Never planned a single inch, unless you want to include measuring every available sq. inch of the basement not devoted to utilities and ordering the plywood and 2x4s necessary to fill it. When the van-load of lumber arrived, I went, "Gulp!" but then plunged right in, making the various sizes of platforms, most 4'x8' w/ 3/4" plywood atop, but some odd sizes, like 2'x6' and 1'x3', here-n-there. Once all the platforms were in-place, and carriage-bolted one to the other, making the whole layout one tight unit, I got appropriately inebriated by the fragrance of all that wood and started figuring out track arrangements and where to - if at all - have a second and/or third level(s).
I wouldn't say I was clever about it all, but I sure had a good ol' time of it playing and letting it all flow out of my creative core.
FrankM.
