To illustrate some of the techniques that can be used in watercolor painting, I used several in a recent demonstration painting.
In the first wash, working very wet, I used salt to create a texture. Small grained table salt and large grained kosher salt pushes the pigment away as it melts. This works for foliage, rocks and gravel roads.
The second technique that I used was scraping and scratching.
In the trunk of the tree, I scraped while the paint was still wet.
Scratching when the paint is wet creates a groove in the paper that will fill in with pigment to create a dark area. When the paint is semi-wet, the scratch marks will not fill in completely, leaving a lighter mark of the color that was scratched into.
I scratched into the foreground in areas where the paint was dry. You can remove all of the paint, right through to the white of the paper when the paint is dry.
Finally, in the foreground, while very wet, I blotted with a soft tissue to lift some of the pigment in random shapes, which were then used to create grass- like textures.
While fun to experiment with, focusing on techniques don't make a painting successful! In a good painting, drawing must be accurate, the values or form must be correct, the composition must be good, and the color correct in relation to the light source. Experiment with ways of adding texture, and the interesting techniques that can add even more depth to your paintings.