A great idea for a decoration would also be a wreath. This is an item that you can make when you have a bunch of small driftwood pieces but no idea what to do with them. The wreath is really simple to make. You just need to glue together the driftwood pieces to form a circle. Hot glue is preferable in this case. The wreath would make a nice decoration for the entrance door or for the wall.
With standing structures, there is much more room for uniqueness. They have a large base upon which there is plenty of room to decorate. They also leave room on tabletops so that the decorator has more surfaces to work with for picture frames and trinkets. There is also not the burden of worrying if a table is sturdy enough to support the decoration.