Forget the prickly job of looping garlands around and around the banister. It's much easier to lay an evergreen swag on top of the banister and fasten it in place with floral wire (available at craft shops and nurseries). Next, snugly wrap it with extra-wide ribbon (such as the 4 3/4-inch chartreuse silk taffeta ribbon used here). To figure out how much ribbon you'll need, measure the banister and multiply by four. You'll have enough for a big, dramatic sash at the newel post.