Some images take longer to process than others, longer to find the right balance and mood. To bring out the qualities in the image that first attracted you. To show the viewer of the image what you saw. That is no surprise, each image brings its own unique qualities, and challenges. Part of learning how to post process images is learning to recognise the issues and the techniques that can best take advantage of them.
Part of the key is to remember what attracted you in the first place. In this case I was sitting watching the showers flow past Mt Tauhara, seeing them lash the Taupo township. The light was beautiful, back lighting the rain, so you could see how the wind swirled over the landscape. Its moments like these that draw people into landscape photography.
But still when I saw the resulting image on the computer screen, I struggled to find a way to bring that same quality of light to the final image. That is when distance can help, help in simplifying and seeing those elements that support the story. By describing it as I did above, the key actors in the story stand out. The light, the way it interacts with the showers and how the wind affected the scene. Then by experimenting, allowing you to play with the elements, inspiration can come. By selectively adding contrast, desaturating and split toning I was able to bring back that quality of light to the showers in the image.
Post processing is not a science, but an art. No one method works every time. Give yourself time, experiment, simplify, and above all enjoy it.