Just thought I'd share that acronym - it stands for Expose To The Right and is for digital photographers. When you expose with a dSLR and some digital point and shoots - you can see the histogram and the basic ETTR technique is to get as much of the exposure information to the right side - or highlight side - as possible without blocking it up.
I know it sounds really backwards, but when I'm setting up a photo, I get my subject/model to hold a grey card for setting the white balance, and a white card to determine the exposure.
The grey card tends to - at least on my Canon dSLR - give a better white balance. But, as I do exposure tests using a white card, I change the lens aperture or adjust the shutter speed until the spike caused by the white card is as close to the right side as possible without blocking up and overexposing.
