As a photographer, when I create an image, I generally have a purpose in mind for the final processing of that image. As a Photo-Artist, I like to play with the image during processing to see what my possibilities are.
To me, all the processing programs available are like a painters tool palette. Sometimes I know the effect I want and use the proper tool to achieve the effect. Other times I push the boundaries of the tools and see what happens. The more I explore, the more I learn about the tools. I also can see what happens by combining effects with each other. The 4 photos above are an example of playing with a programs sliders. I used a combination of black and white along with color to create the different versions of the photo. by masking and blending layers in photoshop I could darken the plane or sky and change the tones. By using different effects in Topaz tools I could change the sharpness, grain, etc. and mix it in Photoshop.
The 4 versions above, are just a sample of the effects I was able to come up with for this photo. I didn't want to bore anyone with the other 20+ versions.
The point is EXPERIMENT. You have nothing to loose, and lots of information to gain. Remember to make note when things turn out to your liking. It is like a recipe for a good cake. Once you have it, make a preset and put notes as to what it does, for future reference.