Ocean Breathing is a yogic breathing technique that I learned from Marcia (Meesha) Albert at the old Elat Chayyim Retreat Center in the Catskills. While it takes a little practice, it is a wonderful calming technique, kind of like your own portable beach. Find audio and written instructions in this New Post in the Gateway of the Sea. As a bonus, enjoy a virtual trip to the beach in Australia.
[Update 12/28/17: the “virtual trip to the beach in Australia” was from an Instagram account that closed, so it is no longer part of the post.]