Take a deep breath in and, on an exhalation, open your mouth and make a loud “haaa” sound, like a lion’s roar.

Source: https://www.huffingtonpost.co.uk/entry/how-to-do-face-yoga-to-look-years-younger-according-to-experts_uk_64edc0aae4b0fcbba8996875

The next exhalation must follow immediately, giving barely any space for inhalation as such.

Source: https://indianexpress.com/article/health-wellness/is-pollution-choking-you-try-these-pranayama-routines-9012738/