I've learned to adopt the 'Hollywood' pose to make sure the camera is kind to my slightly wobbly bits!
It's the one you see actresses adopting on the red carpet to make sure they look good. Hand on hips to make the upper arms look slimmer, shoulders pushed slightly forward to make the collarbones more noticeable, one foot slightly back, suck everything in. The photos end up great, but the pose looks totally contrived!
(The actress in the pictures already looks thin, but you get the idea of the pose!)