A Christmas party at the office is a great opportunity to let your personality shine and express your style. You can opt for a classic Christmas look with a red or green sweater, or go for something more festive with a patterned dress or a sparkly top. If you're feeling creative, you could add some festive accessories like a Santa hat or a pair of reindeer antlers. Just remember to keep it tasteful and professional, as it is still a work event.