Some nice effect you can make in Adobe Photoshop filter Brush strokes - Sumi-e. First picture here is start photo. On Filter-Brush strokes-Sumi-e, you can play with contrast, stroke width and stroke pressure.
In first primer, stroke width is set to 3, stroke pressure - 0 and contrast is 19. On 2nd working photo, contrast is set to 0. You see, 2nd picture is like blur, but first can be interesting with that black mix.