Oddly enough, the majority of people alive on the planet today are breathing incorrectly; most tend to breathe from the upper chest (as you see in cartoons!), but this actually leads to hyperventilation when stressed.
does one do?
Exhale completely, drawing your belly button into your spine
Inhale through your nose, expanding lower belly
Continue inhaling, expanding your middle abdomen
inhaling, expanding your upper chest until your lungs are completely full
Exhale, breathe out from your upper lungs
Continue exhaling, breathe out from your middle abdomen
Continue exhaling, breathe out from your lower
belly, pulling your belly button into your spine
This is a fabulous way to bring yourself back into your body when you feel stressed/panicked.