1. Adjust the photo's size as you like.

2. Duplicate layer (right click on the layer-> Duplicate layer)

3. Reverse the colors of the new layer (Control+ i/ Command i)

4. Blur the photo, (Filter-> Blur-> {you can choose any option. I've chosed gaussian blur})

5. Turn the photo to gray scale on the Expression colors tab. Remeber to do the same to the layer below!

6. Change the blending mode to Color dodge

You should get something like that:

7. Right click on the layer windows (on any layer) and choose "Merge visible to new layer"

8. Duplicate the layer. Change the blending mode of the lower one to "Lighten", and the upper one to "Linear burn".

9. Add tone above the "Color dodge" layer and under the "Lighten" layer. Play as you like with it.

10. Some ereas might turned not as dark/light as you wanted. Use a soft brush (I recommend cloud) to color the parts on new layer

11. This is already looks good! But what of you want to add colors? Here are two ways to add colors:

 

A. Add Gradient map on "Multiply" blending mode

B. (I've tried this one on diffrent photo) for dreamy effect: go to Edit-> Colorize (Techonolgy preview)-> Colorize all

Tip: You can also turn 3d materials to photos. Adjust the material to your liking, than convert the layer to Raster layer

Do notice, sometimes the final black and white background doesn't have enough contrast. To add more, simply duplicate the original photo, arrange as the upper layer and turn the color to "Monochrome". Than change the Blending mode of the photo to "Overlay"

Have fun~