I'm another who hates Christmas jumpers, in fact, I don't like fancy jumpers of any sort. I'd just go with a bit of glitter that can be discarded at the earliest possible moment.
Also I'm fed up with all the magazines, etc. saying that we all need "party" dresses and they all seem to cost a small fortune. I have one posh frock about ten years old that does for all occasions, I've even worn it to a funeral.