There are masses of really good threads here on breathing technique, might be an idea to go and look at some of them.......I know I learned a lot and it's generally acknowledged that I have a 'big' voice......damn thing has a life of it's own, in fact! The trick, for me, was learning to breathe from my diaphragm......think of it as breathing in and out without moving your ribcage, then you can feel where it is.