Take a full length photo
If you want to show off a great new outfit or a fabulous figure after a diet, you will need to stand in front of a full length mirror to capture your body from head to toe. In this instance, your face is no longer the focus of the photo.
Take full body shots in a clutter free space. The photo should focus completely on your figure, not on random objects in the background.
You can appear more slender by slightly cocking your hip to the same side you are holding your camera in. Your opposite shoulder should come forward a bit, and your free arm should either dangle to your side or your free hand can rest on your hip. The chest should lean forward naturally, and the legs should be crossed at the ankle.