Save your used gift cards. Cut the fronts of the cards to make lovely gift tags using fancy edged scissors if desired. Punch a hole in the top of the tag, then thread a colored string (crochet cotton works) through. Package them 20 tags to a cellophane bag, tie with a ribbon, and give out to friends as little 'friendship gifts' before Christmas. You can reuse all occasion cards too by making gift tags and bookmarks!
Source: This recycling idea passed to me by my mother.
My mom used to do this for our church Christmas Sale and they sold like hot cakes. Only she also cut a plain piece of the Christmas card from the back of the card so that the gift tag opened.