Few design techniques can transform a room as the enhancement of its walls.  Wall treatments have never been so exiting and unconventional from highly crafty fluted plaster walls to artistic pyramid paneling walls, architectural motifs that were accredited for exterior texture and furniture have been forever moved inside to residential interiors in never-seen-before ways.  Most of the time the effect is so impressive and powerful that little else is needed to complement the already aesthetic walls.  The more traditional methods such as the ones used in the first four rooms, fluted walls, are not an alternative for DIYers. It is a skill to leave only to professional hands.  The more modern texture walls such as wood block stacking, tiling and origami would be an easier choice for very clever, handy home owner. 
Fluted plaster walls are spiced up with paint and finished up in a curvature a few inches off the ceiling.  I love the round endings, top.  Designed by Jean Louis Deniot via AD.
In this living room fluted plaster walls are taken to the edge of the ceiling and softened up with clear and delicate curtains.  Designed by Miles Redd.
A more austere space designed by Stephen Sills with textured stone floors and wood paneling ceiling in the back room and the textured walls enhance the stern space.
This eating area via Architectural Digest has a softer version of the same fluted walls as they are less deep.  The back wall displays a subtle treatment with horizontal ingrained lines. 
In this family room wall treatment raised the standards.  A proof that architectural motifs are not kept for the outside, they are moving inside residential spaces as well.  Kelly designed pyramid paneling and painted them in gray converting this room in a work of art. 
In a bathroom wall antiqued mirror and slabs of marble are applied on a striped pattern.
This veneer paneling is simply amazing.  Lighting is inside each of the veneer cavity reflecting light up and down.  I can only imagine how beautiful this space is at night. 
For a more organic effect cover a wall with wood blocks of different depth.
This Delta Hex tilesfor the bathroom would bring uniqueness and interest to a modern bathroom.
This conventional paneling wall is spruced up by adding a different design to the ceiling.  via Scandinavian Deko.
A more rustic version of a wooden slat wall.  via Archilovers.
Long pieces of flat wood are stacked up in two different ways to create an artistic effect.  This would be from my opinion the easiest technique to mimic in your home.
An origami wall treatment is perhaps the more time consuming if considered for a DIY project.  The walls in this restaurant in Tokyo are covered with folded paper.  via Upon a fold