A Christmas swag is a festive decoration made of evergreen branches, pine cones, berries, and other natural materials. To make one, start by gathering a variety of greenery, such as evergreen branches, pine branches, and holly branches. Cut the branches to the desired length and arrange them in a bundle, placing the longest pieces in the center and shorter pieces around the edges. Use floral wire or string to secure the bundle, then add pine cones, berries, and other natural elements for extra flair. You can also add a bow or other decorations to the swag for a more festive look.