Some tips I jotted down from watching Chris Orwig's Creative effects videos at Lynda.com...

HDR toning color effects
1. dupe image
2. image/adjustments/HDR toning
3. drop saturation, add edge glow strength
4. copy image on-top of original and add soft-light blend
5. add curves layer specific to HDR layer to adjust contrast

Hue/Sat layer
1. add hue/sat layer and adjust soft-light blend mode on hue/sat layer

2. add color balance layer on top...
2. add color balance layer on top and adjust colors for extra effect

Apply Image
1. copy image layer
2. Image/apply image, blending mode is soft light and experiment with RGB channels