This one may not look like much of a special effect, but in fact this started out as a rather flatly lit, mid day photo. It has a layer of a Topaz Adjust filter called Dark Charcoal that is basically a very harsh grainy B&W filter, which I modified to not be so extreme. This was applied using the luminosity blending mode which only keeps the contrasts and not the color and the opacity was reduced a bit. To this was added both Topaz Impression applied very lightly to boost the apparent texture. I also used Clarity I think to get the colors emphasized exactly the way I wanted them.