Make sure your favorite pets aren't eating your decorations
As someone who has always lived with cats--from when I was a wee fetus till I left for college--our holidays have always been notably tinsel-free. Cats may be known to cause less trouble than dogs to a certain degree, but when it comes to devouring the undigestible, there's no match for them. They're pros. And it gets worse during Christmas, when there's all sorts of shiny, pretty stuff hanging around that's ultimately dangerous for the feline members of the family.
Tinsel is, of course, the most obvious offender. Really, anything stringy or shiny should be kept out of the house if you've got an excitable kitty. The combination of its shape and reflectivity will make your cat think that it's probably prey, or at least close enough to be eaten. And while most cats can swallow tinsel and emerge relatively unharmed from the experience, it's not really a risk you want to take. The cord at the center of the stuff can get wrapped around their intestines, causing a blockage of the digestive tract. This will make your cat very sick and may even require surgery if the blockage doesn't clear on its own.
One possible alternative to tinsel could be stringing up your tree with some necklace chains you're not using. Provided they're thick enough, your cats will have a harder time of chewing them up even if you try. And they're actually made of metal, so they provide that slinky, metallic sheen without being dangerous to your pet.
If you have the type of cat who will chew on wires, also make sure that your tree lights plug in somewhere that kitty can't get at. Try getting power for the strings of lights from an outlet high on the wall, and be sure to tape any hanging wires well out of the way. You don't want your lights to be chewed through and you don't want your cats to get electrocuted. Trimming the very bottom branches off the trees might also help prevent disasters like broken ornaments or nibbled pine needles.
Conversely, the plant so many have considered to be a Christmas culprit isn't actually as much of a danger as you might think. Poinsettias--those pretty red flowers ubiquitous during this time of year--aren't actually toxic to cats or humans. Sure, you might not want bite marks in your Christmas decor, but don't panic if kitty takes a few nibbles--it won't kill her.