Reading the short article about lighting on mixed lighting, ETTR was mentioned in the comments. ETTR means Exposed to the Right. Which means intentionally overexposing the image to lower overall image noise.
Digital Exposure Techniques
The thing is, do Pentaxian really have to do this? Sure if you have a narrow dynamic range shot that you can move the entire histogram 2-3 stops, ETTR will help lower the noise, but honestly with high dynamic range and low noise floor of ISO 80 on the K5 and ISO 100 on the K-3 series camera, I see very little noise even in the shadows after some very minor noise reduction.
I think ETTR really only works with high shadow noise sensors in cameras with smaller or older sensor technology. I find in high dynamic range images (not HDR but images that have both strong highlights and shadows), I would rather preserve highlights since those clip and can not be recovered much past 1/2 to 1 stop, while low iso shadows can be recovered up to 4 stops with some noise reduction. If you really feel noise is a problem in large areas like skies or a large shadow area, you could do a blended exposures or HDR.