"Dear (new’ish) Model, My name is Other Model. I have spent the last couple of years finding out a few things that I wish I’d known from the start. Please don’t think I’m patronising as I mean this only in goodwill, as there is absolutely no gain for me by sharing these cheats. Not all of my points will be valid for you as posing varies in each genre. Just take what you can and ignore the rest. If only one suggestion helps your future career then my time has been well spent. Rule one, the mirror is your BFF. Stand there, perfect your poses and learn how your body shapes. The mirror is a perfect tool to show you what the camera can see – try to imagine it behind your photographers head when shooting and always consider what can be seen from that angle. "
Read the rest here and see all the photos: http://petapixel.com/2013/05/24/dear-model-posing-tips-for-how-to-look-your-best-in-photographs/
Create separation between your limbs from your body. Not only does it prevent the arm/leg from being squashed against you spreading out any fat, it is also an optical illusion for a slimmer appearance in terms of overall width. A basic cheat that makes a massive difference.