This is a great practice for those new to yoga and pranayama. It's also a great practice to help calm the nervous system and ease stress and anxiety.
If you're new to the practice I encourage you to start by laying down and progress to sitting up once you feel comfortable with the practice.
4 Part Breath
This practice is also great for beginners, but is easily altered to work for practitioners of all levels.
Start with an even inhale and exhale, before progressing to the retention of the inhale and extension of the exhale.