These video explains some simple pranayama techniques. Give it a look.

For Bhastrika Pranayama, click here, https://www.youtube.com/watch?v=oOwLfV_jIwU

For Kapalbhati Pranayama, click here, https://www.youtube.com/watch?v=6ZwgFiQuZME

For Anulom Vilom Pranayama, click here, https://www.youtube.com/watch?v=phR3ybQrTtE

Regular practice of these 3 pranayama will make you super healthy. Not only depression, but many diseases will be cured. Through regular practice, your kundalini shakti will also awaken. All your charkras will be balanced and you will experience spontaneous joy. Meditating after pranayamas will take you to a deeper experience in meditation.

Om Shanti.