The single most effective tool

is our breath. It turns on our rest-and-digest parasympathetic response, our calm, our clarity, and our spirit.

Sit with your spine tall, close your eyes, and breath through your nostrils, including on the exhale.

Expand the body on the fullest inhale you can make and breath into your solar plexus (just below the diaphragm).
Exhale as completely as you can, muscles of your core pressing in towards your spine, spine remains tall like royalty.
Continue.
Let your thoughts and any tension melt away with each exhale, and then
inhale in pure energy and life force.