First John congratulation on seeing them hope it was a great experience! I got hooked years ago, now go back when I can and its a long trip if you don't see them
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Anyhow I have actually asked this very same question many times with few answer.
Here though it is little, is what i have discovered mainly by working it out for myself.
First the most difficult to work with are files that have a fair amount of light pollution, I had one particular shot that I really liked and I recall working on it for hours.
I basically duplicated the image and worked on one to try and get rid of the light pollution. I used a combination of careful adjustment of white balance then into the Hue / Saturation and adjusting, mostly the Reds / Oranges / Yellows.
After I had got as much of the pollution as I could removed then I blended the shots together using layer masks.
I have found that altering the colours in the Aurora a big mistake. If you make any changes to the hue or saturation they have to be very subtle or they will look awful.
On one shot I did have a number of exposures much the same so masking out the Aurora I stacked the image which greatly improved the look of the stars.
If you were in a dark sky area then I found that less is more when it came to processing. Gentle and careful adjustment of white balance. I found with some shots that using "fluorescent" or "flash" was the first step toward a better looking shot and makes a good starting point. That's about 4000K - 5000K.
I hope this is of some use, if I think of anything else I will add it to the thread.