I'm not the most lean person on the planet, and many pictures seem to really point this out. While I wish I was simply in better shape, it is simply not the case for me or unfortunately, many people.
Are there poses, lighting techniques, focal lengths, etc. that will work better to reduce some of the common overweight features (large stomach, double chin, etc.)?
Update: Ok, so I incorporated a few of the suggestions that I could into a self portrait in the limited space I have. I didn't have suitable room or patience for a three-quarters shot, so here's just a headshot. Some of the suggestions really, really made a noticeable difference.
Its a picture of me I actually like! (I pushed the DOF a little shallow though, and the back of my ear is out of focus.)
Second Update: So here's another shot that takes into account a few more of the suggestions yet (including Jay's suggestion of slightly rotating the light a bit more). The only thing I think I'd additionally do is make sure to where a higher collared shirt to help hide neck rolls. Also, I found straightening my back fairly rigidly helped a lot.
And in finale, here's a before picture of how bad it could look. This was taken about 30-40 pounds lighter, by another photographer. (This is a lowres crop, unfortunately.)