I choose this photo because I liked the complicated shape and saw the clean color contrast and thought it would be an excellent first photo to work with. I was able to use a different mask from one of the color channels to pull a suitable mask for my sky replacement. With a bit of color correction to get the pipes to have a slight blue tint from the sky, I also decided to have some fun with this and added additional elements to the photo like a fake pillar of steam and a phony airplane.
I once again chose this photo for my second sky replacement as the difference between land and sky on the horizon line made it easy to pull a difference mask. I tried something different with the atmosphere and used a gradient tool to allow some atmospheric perspective as it nears the horizon. Next, I needed to mask out the river and add the reflection of the mirrored sky into the river. The image reflected in the river is not a perfect mirror reflection but is instead slightly offset. I figured that due to the angle of the landscape the portion of the sky we would see reflected in the river would be out of frame. I then added several filters to make the sky appear to be affected by the ripples in the water.