The floral designs work really well for the romantic setup. What you may want to try out are floral patterns with some fine lines and the damasks. The colours you choose should be muted to get the right effect. You can also go for the pastel colours.
Casual Look: If you want to give your room a casual look, then you will want to go for the faux finish. You can go for the Ultrawalls decorative wall paper with faux finish. You can take your pick from the simple stuccos or you can also go for the beadboard designs.