Sorry for the dark crummy picture (no flash).
Most of us have, at some point, spray painted branches or bought them pre-painted to use for centerpieces. A cool thing I did the other day was spray paint a dead tree that I was going to throw away. (I have a limited green thumb.)
I sprayed it with silver spray paint including the dirt and cheap plastic pot. I hung metal words from it that read "spooky", "boo", "trick or treat", etc... and put one green apple in the dirt with a crow.
There are so many things you could do to this - group several together for greater impact, add spider webbing, crows in the branches, black bows, hand from the ground, tombstone, etc... or nothing at all for simple eerieness.