Wendersnaven.com (a resource for nwn2 builders)

I opened one of the OC areas to see what settings they defined for realistic firelight (torches, candles, fireplaces, etc). Based on that, these are the settings I am using for basic light sources:

Behavior

• Lerp: False
• Flicker: TRUE
• Flicker Variance: 0.05
• Flicker Rate: 18
• Flicker Type: Jumpy

Shadows

• Cast shadow?: True
• Shadow Intensity: Between 0.3 and 0.6 depending on how it looks.

You may also want to nudge the colors just a bit towards red and orange. Not to the point of being overpowering, but just enough that it's not plain white and gives a subtle red/orange undertone.