Knowing that in general, people seem to like semi-black and white portraits, I thought I would try a variation. Instead of making the entire scene semi-black and white, why not make the background 100% black and white and the model semi-black and white?
To start, here is an over-the-top HDR background taken at my friend Carlo's beautiful home in Chiang Mai, Thailand:
Here is the original studio image of my friend Anne:
To achieve the result we want, we convert the background image to black and white and vignette it. Anne was masked from the seamless paper, converted to black and white, positioned on the background, and the layer opacity set at 90% to give the semi-black and white look to just her. Remember that a color version of just her must be beneath the black and white layer. If not, the background will start to show through when the layer opacity is set to 90%, instead of the color version of her. Here is the result: