At RC Astro, we enthusiastically believe that an important part of the joy of astrophotography is learning for yourself the best order in which to apply the various processing steps that lead to a finished image. As a result, we do not prescribe workflows. To do so would replace your personal voyage of discovery and learning with cookbook answers: you might know what to do, but you wouldn’t know why. Moreover, dictating a “proper” order of processing steps would prevent conscious thought and innovation on your part – one workflow may work well for a particular type of astrophotograph taken with a particular class of instrumentation, but it might not work well for all images.
The story of astrophotography is one of constant innovation, and it is far from over. Many of the techniques and workflows of yesterday have become obsolete as new and better methods have been invented – invented by individual astrophotographers closely inspecting what is happening to their data at each step, and trying to dream up a better way.
Instead of cookie-cutter answers, we try to give insight into why applying one tool before or after another might be good or bad practice. As an example, we can confidently state that noise reduction (of any sort) should not be applied before deconvolution (of any sort). Noise reduction tends to destroy the low-contrast information at fine scales that deconvolution needs to function well, and it gives the deconvolution algorithm a false sense of the signal-to-noise ratio in the image. Applying deconvolution after noise reduction may produce an image that “looks sharper,” but the accuracy of those sharper details would be highly questionable.
Beyond general guidelines such as this lies a wide vista of possibilities. Experiment for yourself. Study, learn, and experiment some more. Inspect the results of a particular workflow and ask yourself why that workflow produced that result, or why one processing sequence worked better than another. Think critically about the results you are seeing. It is through exploration like this that you will eventually master this fascinating avocation, and perhaps one day come up with a new approach that no one else would have thought of.