Given the the controversy over the past couple of weeks, it would be interesting to see an expanded article that would summarize (and simplify) the various ETTR possibilities -- or perhaps two or three articles summarizing different views. As I have mentioned in my comments, I'm not so much interested in an engineering discussion, as in a "prescriptive" article or set of articles, that would deal with the when and how-to aspects of ETTR...if it's to be used at all. The various arguments have left me seriously uncertain about procedure...
Well, I'll kick off with a few methods that have worked for me.
(1) First one should attempt to get the histogram and 'highlight flashing' as close as possible to the ideal RAW histogram, bearing in mind that the histogram is based upon a jpeg from the RAW data.
To do this, in my experience, requires adjusting the camera's jpeg settings so that the review image looks very lack-lustre and unappealing, so much so that you wouldn't want to show people the image you'd just taken in case they thought you didn't know what you were doing, or in case they got the impression their P&S was sooo.. much better than your expensive DSLR.
Such adjustment of the camera's jpeg settings will need a bit of experimentation. You might find you need to set contrast, saturation and sharpening at a minimum so that the 'highlight warning' doesn't flash when the image is still underexposed, from the RAW perspective.
(2) Buy a new camera which has a linear noise and dynamic range response (on the graphs at DXO Mark) that reduces by one f stop (or EV) for every doubling of ISO, so that there is no fundamental image quality advantage to increasing ISO.
The Nikon D7000 and Pentax K5 are in this category. With such a camera, you have only one worry regarding ETTR, and that's inadvertent overexposure at base ISO.
Unfortunately, the review image with this method can look even worse than the first method, if you've been underexposing at base ISO instead of using a higher ISO. It may be so dark you can hardly see it at all and you may have to flatly refuse to show it to anyone in order to protect your reputation.
(3) Take the time and trouble to obtain a correct exposure for ETTR purposes before taking the shot. One effective way of doing this, using the camera's in-built exposure meter, is to set the camera to spot metering mode and, using a single focussing point, take a reading of the brightest part of the image you want to retain detail, then increase exposure by approximately 3 stops, depending on the model of your camera. Again you will have to experiment to determine whether that increase is 2.5 stops, 3 stops or 3.5 stops.
(4) Bracket either exposure or ISO. This is my favourite method because I can keep the review image looking bright and sparkly to impress the beautiful female subject I've just photographed.
There may be other useful techniques for achieving ETTR, but those are the ones I've tried and that work for me.