In most homes walls are flat planes which separate or define a space. What becomes boring as hell is when every wall surface in a home is exactly the same. Paint, paint, paint, paint all the way around. Live a little!
Granted, most walls are not and shouldn’t be the the focal point of the room, this does not mean they have to be boring. Consider the wall another space to add texture. It can be physical texture, or purely visual. A wallpaper or application which gives the impression of a texture but is, in the end flat is what we mean by visual texture.
Here are some interesting ways you can add texture to your walls from the easiest and inexpensive to the most difficult. Some are DIY-worthy and some require hiring a professional.
EASIEST 
Wallpaper is the quickest and easiest way to add (implied) texture to a wall. Beaded or embossed wallcoverings have a physical texture. Wallpaper offers an instant transformation.
EASY 
Paint and applied texture is completely DIY worthy. Plan it, buy it, stick it, paint it. 
Depending on your artistic skills you can take it a step further like in this nursery where the wall is ragged, stenciled and then tiny glittery embellishments are applied.
SOME SKILL NECESSARY 
Upholstered walls are doable, there are plenty of online tutorials to get you going if you are the least bit handy. Walls can be completely upholstered, we love to do this in powder rooms especially if they have tile floors, or as inset panels like in the bedroom here.
CONTRACTOR WORTHY 
Wood paneled walls have been around for centuries. It can be very elaborate like in this historic home in Hyde Park, NY. 
Nowadays our wood or wood-like panel options offer very cool textures. 
Masonry makes for great texture and by all means don’t be afraid to paint it! 
Tile doesn’t just belong in a bathroom or kitchen. A great tile mosaic, decorative or purely textural tile can add interest to many interior walls.
ARTISTRY REQUIRED 
Plaster applied with a palette knife is a old-world skill which has been appreciated throughout history. The right artist can make plaster work wonderfully modern or historically accurate to coordinate appropriately with the architecture of a home. 
True textured walls requires skill or it looks like a juvenile art project. Note: that popcorn spray on crap is not what we term textured walls. I’ll repeat, spray on texture = crap.
The world is not flat, life is not flat, nor should every wall surface in a home be flat, the same ‘ole flat surface it came with. Blah! Give your walls some interest. If one room is flat give an adjoining room some texture. Vary your walls, not all flat and not all textured. Interior walls are as diverse as the world, they deserve to have a little personality.
