I used to decorate the tree with a lot of little bird ornaments made from feathers. When I got the cats, it occurred to me that this might not be a good idea. I found some Christmasy cat toys, and hung those on the tree, and the cats wouldn't go near a 'cat-safe' tree. I've been putting the birds on again, along with the Star Trek ornaments, and shark that says "it's beginning to taste a lot like Christmas".