Hi Mari,
We tend to breath from our chest watching it rise. But I was trying to feel just below the belly button and the Psych refreshing my breathing said above the belly button, put little finger about belly button waist area and feel from there where we want to build strenght to the diaphgram. Concentrate on feeling it rise.

Instead of how I had retreated to puffing my chest. In times of stress, which seems daily for me I go back to that chest puffing and rising.
Hope that helps if I find a link I will post,
di