Here is a small N-scale layout that I put together using a scrap of chipboard that had foam already glued to it (I think it has to do with roofing although I don't know what the product is called.) The foam is fairly soft and carves easily, but it won't hold up will to rough handling.
I carved out a stream channel and ran a simple loop of track around the 2' x 4' piece. I also added a small styrofoam mountain in the one corner. I only had one tunnel portal, so I hid the back entrance to the mountain where you wouldn't be able to see it easily. I covered the stryofoam additions with sculptamold and painted some of the remaining layout with brown paint. I didn't even bother to paint over the sculptamold. The part that wasn't painted looked a lot like snow, so I just added the Micro-Trains Village pieces to the layout. I also placed six cars, the loco, and caboose from Micro-Trains' 12 days of Christmas cars on the train.
There is a lot to be done yet, but this is already a different look than it had last year. It looks more like a snow scene with the snow covered buildings. Last year I just had some structures that I grabbed off of my layout. Next year perhaps I'll have some skiers coming down the mountain and a ski lift.