Start with 4-4 breathing: 4-count inhale and 4-count exhale. Work toward decreasing your inhale count so you get used to inhaling a lot of air in a short time.
Full playlist:
https://bit.ly/33XXUbz
Link to all scores: https://drive.google.com/drive/folders/16CXXlRWPsCFrygBev72RQcPR7547_pSe?usp=sharing
