Do the tuck pose, 3/4 posing, and accentuate your subjects on the shadow side rather then the highlight side. These are some basics that will thin them out. Also shoot down at your subjects, in addition don't have them sit(as flesh will fold and garments will ride up). I also have some of my clients breathe in and hold it, like they're anticipating a kiss or a hug. Have your clients shift their weight away from the camera, towards the rear hip for both guys and gals. You can also use the garments like the veil, train to cover some body parts. Shadows shadows shadows and 3/4th posing is key!