Well, that depends on the kind of tree and the size of the ribbon. If it's a small, narrow tree, you can just wrap the ribbon around it in a spiral, starting from the bottom and working your way up. If it's a larger tree, you can try wrapping the ribbon around in horizontal lines, or you can create a pattern of diagonal lines. It's also a good idea to secure the ribbon with tape or pins to keep it from sliding down or coming loose. And don't forget to add some ornaments and lights for extra festive cheer!