After a stressful day it is tempting to jump straight into a vigorous vinyasa yoga practice to sweat and breathe away the day. But before you do take a moment no matter how short to observe yourself - mind, body and breath - before you start to move. If you have a very yang lifestyle you might need a few yin moments of calm and silence before you get stuck into your asana practice. You might find that by embracing the stillness you are less inclined to over exert yourself to the point of depletion and more likely to go with the flow and find yourself in a more energised, calm and balanced place.
Take a comfortable seat. Start to notice your breath. Breathe deeply through the nose. With each cycle of breath repeat the internal mantra 'I am breathing in' on each inhalation; 'I am breathing out' on each exhalation. Repeat for a couple of minutes. This is an incredibly simple and effective calming technique. When you are ready, transition into your more physical practice. Return to this breath throughout your practice if you find yourself getting distracted.
This simple meditation practice can be used before, during and after any form of exercise and can applied in any situation when you need a mental timeout.