4-7-8 Breathing This technique places the body into a state of deep relaxation. I use it post my workouts or long stressful activity .

Take a breath in, then exhale through your mouth with a whoosh sound.Close the mouth and inhale quietly through your nose to a mental count of four. Hold for a count of seven. Exhale completely through your mouth, with a whoosh, to the count of eight. Repeat this cycle for at least four breaths. A video is illustrated here.