The photo above was taken in Blair Atholl in the Scottish Highlands. I liked the original image in color, but I thought that it needed some "pop." I am a big fan of rowan berries, and wanted them, and the rowan trees, to stand out. I was able to do this using layers in my photo editing software. There are a number of photo editors that will do this, such as Photoshop and Lightroom. I use Aurora HDR 2017, a powerful, professional photo editing software package, and an upgrade from Aurora HDR, which I have been using for over a year now. I originally found working with layers fairly daunting, but Aurora has a wide variety of video tutorials, which makes understanding the process much easier, especially for "old farts" like me!
To achieve this effect, I open the image (or images, if I have taken a number at different exposures) in the software. At this point, I can adjust HDR (High Dynamic Range) effect, color saturation, exposure, contrast, etc. Next, I ad an "adjustment layer." On this layer, I can make further adjustments. In this case, I completely unsaturated the color, which turned the image to black and white.
Next, I opened an eraser function, and got to work. With the eraser function, I have the ability to adjust the size and opacity of the eraser. In this case, I set the opacity at max, and adjusted the eraser size as needed for different areas. With the eraser, I was able to "erase" the black and white over the areas that I wanted colorized. After about nine hours (not in a row), I was able to achieve the image that you see here.
Using layers, it it is possible to produce a wide variety of effects to your images, but I really enjoy this effect, and have used it on a number of images from street scenes to close up shots of flowers.