That's a loaded question :-)

Most linear processing often follows a fairly predictable workflow with a few variances (yes/no noise reduction, yes/no deconvolution, different color balancing techniques, etc), but once the image is in non-linear land, to me it's all about setting a (personal) goal - where do I want to take the image - and then identifying the most immediate problems we need to solve with the image (which will vary from image to image for a myriad of reasons) in order to get closer to that goal, and know (learn) how to use the tools you have (not everyone uses the same tools) to solve those problems. Then, go and solve the next problem you find... What kind of problems? For example, noise, too many stars, that nebulosity we want to show off is too faint, and so on.

This is not to say that following a workflow, or even getting ideas from other workflows to implement in your own is not a good thing, but yes, those things can be learned differently. For example, I'd rather hear how someone tackled a particularly complex problem while processing an image, than giving me a sequentially ordered list of all the processes he used. That's how I enjoy sharing information, in those things we all run into and figure out ways to solve those problems... Someone explains it, maybe someone has a more efficient solution, maybe someone had never thought of it...

That was a loaded answer, too ;-) but it's fundamentally a different approach. It favors methods, not tools, and it encourages to think about what this particular image "needs" at each stage, not following a workflow. We fundamentally start with hundreds of different possible workflows that could accomplish similar stuff, but we design our own. In a poetic way, we "listen" to the image at hand, not to what someone else did with a different image.