The list of techniques presented here is in all likelihood neither complete nor comprehensive, but from what I have researched I'd say it covers a great percentage of the methods in use. This techniques has appeared on the HBD in the past. Gravities of around 1.010 to 1.020 are used, and roasted or crystal malts can be added to enhance character. I tried this method a couple of times, with barely passable results. Also, go easy on the hop levels.
Acidification definitely helps.
Also, because of the low malt content, there probably isn't enough residual protein to give decent heading, though heading agents could perhaps be used to compensate. The change in gravity is due to the conversion of sugars to alcohol, CO2, water, and other yeast by-products. One snag is that other yeast by-products, for example esters, are often desirable and would only be present in low amounts due to the minimized yeast acitivity. This might be a good place to start your research. Back to my porter.