Wool picking method
Picking is used when you need to place the wool on the surface, creating texture.
Picking allows creating flat fine nubs which form a unique texture of the surface.
For picking take a piece of wool and fold it in half. Hold the piece near the fold with one hand and start pulling out fine slivers with the other hand, while leaving all the wool in your hands.
By doing so you shall get a wool nub.
You can flatten it a little and form a spot of color with blurred contours.