This image was a collaborative effort with my Rose City Astronomers clubmate Kevin Morefield. The data is all mine, but he provided a lot of guidance on the processing. He encouraged me, with great success, to start using Photoshop as a bigger part of my workflow. This is my first time using it to a greater extent than to put final touches on an image using Camera Raw Filter and maybe some final noise reduction. 

This image is comprised of six image layers and 7 adjustment layers. I had a lot of fun experimenting with layers and dynamic mixtures of various elements of different images such as using the luminance of one image and blending in a portion of the colors of another image. This made for a far more interesting experience in processing with some excellent results. 

Huge shout-out to Kevin for all his guidance and support on this image. I couldn't have done it without him. Thanks, Kevin!

Workflow is as follows:

PI:
DrizzleIntegration
Separate RGB channels
Linear fit on R
StarAlignment thin plate splines
RGBCombine
NXT through mask protecting highlights
MaskedStretch
HT to finish main stretch
HT to align color channels
SXT
HT on stars to correct colors
Save stars for PS
Separate RGB channels
Save R for PS
Heavy NXT on B channels
PixelMath - Create pseudo luminance channel with 40% R, 30% G, 30% B 
Save for PS
PixelMath - Create new RGB image - R=R, G=R*.5+(G*.5+B*.5)*.5, B=B*.5+G*.5
Save for PS
Create yellow color mask using Script>Utilities>ColorMask
CT through yellow color mask to create red/yellow color gradient
CT (no mask) to subtly boost blue and green curves in the highlights - 2 iterations
Save for PS

PS:
Layers:
Stars (screen)
Levels
Hue/Saturation (masked to blues)
Hue/Saturation
Vibrance
Brightness/Contrast
Brightness/Contrast (masked with luminance from Starless)
Starless w/ Color Curves (color)
PseudoLuminance (luminance)
R (overlay)
Hue/Saturation (masked to yellows/oranges)
Starless copy (color)
Starless (background)

Apply CRF  to Starless copy
Add Hue/Saturation adjustment layer    
    Hue -10
Apply CRF  to Starless w/ Color Curves, set opacity to 25%
Apply levels adjustment to R layer to enhance contrast
Apply Unsharp Mask to R layer at 28px, 168px
Apply levels adjustment to PL layer to enhance contrast
Apply Unsharp Mask to PL layer at 28px, 168px, 336px
Add Brightness/Contrast adjustment layer
    Brightness +13
    Contrast +20
Add Vibrance adjustment layer
    Vibrance +20
    Saturation +20
Add Hue/Saturation adjustment layer, set opacity to 50%
    Hue -10
    Saturation -10
Duplicate Hue/Saturation adjustment layer, color mask to blues
    Hue +12
    Saturation +60
    Lightness -17
Add Levels adjustment Layer
    Midpoint 1.2
Add Brightness/Contrast  adjustment layer, masked using Starless luminance
    Contrast +95
Layer mask painting to protect highlights from several adjustment layers
Turn off Stars layer
Save for PI

PI:
Add stars back in using PixelMath ~((Starless)*(~Stars))
NXT through mask protecting highlights
Save for PS

PS:
Crop
Add grain
Export