We're working on a project where painted horizontal paneling will adorn the walls of a grand masculine foyer. It is such a simple and inexpensive treatment to do, but it's rare to see it in modern interiors, as paneling has a bad reputation courtesy of the vertical wood-grain varieties of the 1970s.
Because they're horizontal, these panels draw the eye out to the furthest edges of a space, making it feel larger. They add just a bit of texture without being as splashy as wallpaper, or as plain as paint. The process is simple: cut panels to size, install them with about one-quarter of an inch of space between each plank, and that's it! You can pre-treat the pieces with paint or stain, and experiment with contrasting colors popping out between them for a more lively effect.