Not sure about the dead tree. However, I do have some tips:
1. For the creepier houses, put trash all over the empty floor spaces. It makes it seem as if something bad happened...
2. Music: Hypno K.K. in a music box, or just playing normally. Music boxes are cool if you put them in front of a doll, though, so it looks like they're listening to it.
3. Designs. If you're not very good at drawing creepy things to hang on the wall, you might have some trouble, but with a little help you'll get it right.
4. For the outside of your town, TT a few years into the future so there are weeds everywhere. Then leave your 3DS open for a while so the grass wear will start to increase.
5. Make sure you have 4 characters so you can have max designs and more scary houses!
6. You'll need a lot of money. If you're trying to get spooky sets and items like that for your home, you'll need a lot of money; try to get a lot of money in the bank and TT 2-3 years ahead, collect intrest, and repeat.
7. Make sure that when you update the dream, it's after and close to 12 AM in your game (12 AM exactly is the best.) so that any TVs will have that staticy look on them.
8. On the outside, put a lot of pitfalls in the ground- tricky pitfalls are even better.
9. Make sure all the houses are in an order so that people don't go to them differently and get whatever story you're telling confused!
EDIT: The tree has no leaves in winter. The snow might be a little odd though, unless you can find a reason that it'd be winter in the town.
