When getting ready for Christmas in a home where you have no clue how the animals will respond to decorations, the tree, lights etc. can be an interesting, frustrating and sometimes amusing endeavor. After several years I have a system. Phase one is to put up the tree. Just the tree. If the tree stays upright over the next few days then I get to put on the lights, and maybe even turn them on. Then we wait a few more days. Next come the other decorations, the ones for the house, not the ones on the tree. The tree doesn't get decorations until at least a week and a half but usually two weeks after the initial set up.
If I decorate the tree first the unbreakable, unscratchable and generally indestructible decorations go up. If they stay on the tree then those that could potentially get wrecked go up. Never does a breakable ornament go anywhere that a cat can go. Coming home to bloody paw prints kind of freak a person out.
I've had cats in the tree, and have had to pick up decoration continually from the floor. Items have been broken, chewed, peed on, pushed off counters, hidden, or sometimes completely ignored. Joseph from the Nativity scene has literally lost his head. This year I have a tree fully decorated as Tan has chosen to ignore the season completely.