Whenever using Adobe Photoshop to change the look of a photograph, I try to be decent using the software. Decent meaning, I never add things to my photographs.
There are software components out there that replace the sky automatically, but those things I never do. Then what do I do in Adobe Photoshop? I remove things – things that are distracting to the eye in a photo.
Sometimes there are things in a photo that do not belong there, and I was simply unable to change; like dirt in an ocean or here in this photo a manhole and some graffities on the wall. Look at both the photos to see the difference.
I use the “Spot Healing Brush Tool” in Adobe Photoshop to remove objects. Hit [J] on your keyboard to activate it – make sure that “Content Aware” is enabled on the selection at the top. Select the size of the brush and start removing!
When it is just sensor dust, I use the Adobe Lightroom function for this (Keyboard [Q]). But when it is more complex I think that Adobe Photoshop does a better job.