I'm working on what it will look like right now. I used FastTrack last year on both layouts. I took down the one in the train room and used my collection of SuperSnap. I didn't really do anything about the loops in the living room and ended up not running it much. Even on a blanket on the carpet it just sucked.
So this year I decided to try an old school O27 layout. I have a fair amount of curves and straights and switches. I then found some Marx O34 (2 full loops) and a loop of NOS low profile O42. I have them on the train table right now. I'm trying to see just what I can do with it. Though loop in loop looks to be it. I have a Lionel Stop Station I would finally like to use. And block, dwarf, and semaphores signals and a 2 track signal bridge. I'm hoping to get most of them on for the red/green lights. I also have a Lionel Christmas belt loader and oodles of passenger platforms, but most aren't lighted so I will be adding lights to them as I have time. I've picked 2 inch foam for the base. The tree will either sit on it (the stand fits comfortably inside an oval of O27) or as my wife suggested be coming up through a proper sized hole cut in the foam with the board up far enough to clear the legs. Not sure exactly yet. The tree has individual branches so we can give the trains plenty of clearance. This tree is "my" tree for all my Christmas ornaments - a 2 sets of Lionel balls, Hallmark Lionel ornaments, my C7 old school lights. My wife found a caboose at a craft show that appears to be part of one of the cheapie China train set that runs on batteries and was all tarted up for Christmas. It's glued to a piece of the straight track and we used as a tree topper last year. I'm going to see about adding light(s) to it. Plus when ever we go on a vacation or a road trip or to a train museum where there is a Christmas store we get all the train stuff we can find.
I only have one oldie, a 685 Hudson I pull my PRR Madisons with, a Happy Holidays RS3 (that runs on O27 curves), a PE set, a NPC 4-4-2 with the passenger cars, and a LC Silver Bell Express. And a NPC 0-6-0 that I have to replace a board in after an unfortunate accident last year. If you're gonna use a ZW-275 get circuit breakers! I found 5 of the Lionel 91? and they work. Took some adjustment but they will trip on a derail and save your electronics, your wire and other things. It's Ok, we're getting new carpet anyway - live and learn. That and the TVS on every post to common.
So, yeah it's to early to put up but planning is something else.
As to smoke - I use Megasteam. I love Christmas Pine, Bayberry and another that escapes my mind right now. But the pine is my favorite.
I watch The Santa Clause cuz at 62 that's what I want to grow up to be.