Did you consider using interior wall paneling the last time you decorated one of your rooms?
Wallpapers or painting are the ways which come to mind. Using panels is of course more time consuming and probably more costly, but if you want to give your room a completely new look it's certainly an option you should consider.
Think of how different your room could look if you not only change the color and texture of the walls, but the actual material itself.
Wood paneling - the natural choice
Although there are a number of materials you can use for your interior wall paneling, wood is probably the most adaptable.
It looks good in virtually any style of interior, because there are many ways in which you can apply it.
It can be installed from floor to ceiling, from floor to chair rail height, or to picture rail.
You can leave the wood in its natural color, or you can stain, paint or grain it with any paint finish you like.
Types of paneling
Traditional fielded paneling (where the central area is raised above the framing) looks really great in a period home. Tongue-and-groove is less expensive and is one of the most used methods. This is often used for pine panels.
Believe it or not, but you can even use plywood, especially if it's given an interesting paint or stained finish, and beadings or molding are fixed as well.
The thin 'matchstick' panels which look so attractive in many homes on the East Coast of the USA is another option you should consider.
If you're not proficient in woodwork or DIY, then don't even think about installing your interior wall paneling yourself. It really is a job for a professional.
Paneling needs to be hung by a carpenter, as it's important to fix the wood to a framework of battens which are screwed to the walls.
If the wood is relatively new, you'll need to leave it in your home for a few weeks or even months to allow it to acclimatize to your home.
If you don't, and you fix it to the walls immediately, you may find cracks and gaps opening up as time goes by.
If you plan to buy new wood for your panels, you might like to make sure it comes from sustainable resources (that is, new trees are planted to replace ones cut down).
Use old wood
You'll probably be able to find local businesses who specialize in reclaiming wood from old properties which have been demolished. In this way you're able to buy genuine old wood, such as oak panels, which will give your room a real historic look.
These companies are also a good source for wood floorboards, and other usable items for old properties.