Breaking it down into practical rules for simple minds (like mine):
- Use full stop ISO's
- Only raise the ISO when the exposure can't be further increased by shutter speed or aperture settings.
- In low light, better to raise the ISO than to increase exposure in Post Production
- Noise reduction in camera is not effective
- Post production noise averaging works well when the subject is stationary and a tripod is available
- Auto ISO has a tendency to push the ISO higher than necessary and should be avoided in low light situations
Ok, that's pretty much what I've learned over the last couple of days. Please let me know if I'm incorrect, missing anything critical, or need to do more reading!