How Should I use smudge tool and when? !! ??? ???

I can't Explain you exactly how to use it .... but i can show you an application

 

The main application from me is to make someone thinner or fatter :P

 

I can show you an example ...

 

The origilan:

 

 

Now Thinner:

 

 

And thinner (It's a little bit Freaking :P) :

 

Ok man thx i got it!someone lock the topic plx!