The mistletoe tag is made with the same stamp I used for the card. I love this stamp -- the greens and red are so pretty together. I added a gold sheer ribbon which I think gives it a more formal look. String or yarn would be great for a casual touch. I taped a 'To / From' sticker to the back.
The Merry Christmas tag was super easy to make as it is a free printable. Simply cut around the edges of the tags after printing, punch a hole and add ribbon. I used the same gold sheer ribbon, but a red would be great, too. Depending on the wrapping paper, black might be work.