I do my best, though it's not always easy. There's been a couple of years (not consecutively, mind you) where it was significantly damaged during moving. One year, seemingly beyond repair, and I just left it a shambles, because that also happened to be Season 39 when they made a number of significant changes to the set and I was torn about how I would accommodate them on my model since, at that time, I always tried to make it look exactly like on the show as possible. IIRC, I think when I made my mind up to rebuild it, I was up till like 3 or 4 in the morning doing, and that was when I decided to leave it in "Permanent Season 38 Mode" for a couple of years before I gradually began redesigning it to what it looks like now.
One thing that's helped is really gluing everything into place to ensure it'll stay put: prior to that, I just used tape, which wasn't always strong enough to do the job.