After having found the perfect piece of Ponderosa pine in the firewood pile, this is how I start a Zigzag wall piece. With an axe working my way in to a square piece of wood.
With my japanese precision saw I start cutting the first triangle.
This wood has such a beautiful color. The heartwood in the middle is a nice pinkish color while the sapwood has this darker blue gray tone. This blue gray color comes from blue stain fungus. It's really beautiful and will not decay, now that I have taken it out of the rain to dry properly. The wood comes from a dead tree, and sometimes one can be lucky to find the wood when it has this color. Not to much and not to little.
After having shaped the wood into a ZigZag wall relief, and its all sanded smooth and nice, I let it absorb lots and lots of linseed oil. That will prevent it from drying to fast and cracking.