For a casual Christmas party, you can't go wrong with a festive outfit. Consider wearing a red or green dress with some sparkly accessories like a necklace or earrings. Alternatively, you could wear a festive sweater with a pair of jeans or leggings and a pair of cute boots. Add some tinsel, holly, or mistletoe in your hair for an extra dose of holiday cheer! Finally, don't forget to bring a cozy blanket and some hot cocoa for a truly festive vibe.