For an unexpected texture, hang a wire basket. They work well with a range of styles, from vintage modern to new traditionalist. You might enjoy them plain and empty as sculptural elements or with objects such as small prints or postcards arranged inside them.
This list is just the tip of the iceberg in terms of baskets that look great on walls. I’ve seen round laundry baskets mounted sideways to hold stuffed animals in children’s rooms, as well as bread baskets mounted above dining room buffets. Keep your eyes open for interesting shallow baskets and picture them hanging on your walls every which way.