Nostril flaring breathing
In this exercise, I tense and relax my nostril muscles rhythmically. Nostril muscles are just like any other muscles; not using them for an extended period may lead to a limitation, or even a loss, of the ability to flare the nostrils. I emphasize nostril flaring when holding my breath, but it’s also possible to flare the nostrils in other breathing stages. For example, flaring my nostrils when inhaling or exhaling. I sometimes imagine there is a flower close to my nose and that I’m smelling its pleasant scent while flaring my nostrils.