Simple practices can have a big impact. For example, box breathing is a technique even the US Navy Seals use to manage stress. In this method, you follow a pattern like the four sides of a box: breathe in for 4 counts, hold for 4 counts, exhale for 4 counts, and then hold again for 4 counts.
Box breathing helps reduce stress, calm the mind, and can even help with issues like indigestion. It works by activating the calming part of our nervous system. For more on its benefits, check out an article by specialist Melissa Young from the Cleveland Clinic.