The trick to this one is to really expanding the diaphram and lungs so it's really stretched to the capacity. Really stretch the diaghram  like a balloon like you cant inhale anymore. Really stretch those lungs...this helps to release all the emotions in the diaghram. Some people like to bring their tongue in when they exhale. Tell your body to relax. Spine is straight. Extend the breathe when exhaling and pull the navel in.   Just start to observe your thoughts like clouds passing through the sky. even when you are doing a simple pranayam you can really just sit in the silence within and allow the breath to do the work. Sitali pranayam...spending a few minutes meditating can change your life.