… and then slowly exhale.

Actually it would be great if you can keep the breath inside before you exhale again and make your exhalation double the length of your inhalation.

You can count for that. Repeat as long as it feels right, but at least 3 times, to release some stress. Another important thing is to breath out completely, to empty your lungs. Got it?

This technique should create awareness of your breath, deepen it and eventually calm your mind. There are plenty of other good sides to regular breathing exercises like increasing your focus, can help you meditating, strengthen your nerves. If you regularly exercise your breath will become deeper.

You can feel the difference after a couple of days or a week of practice. You will feel re-energized, much clearer/more focused and how the volume of your lungs will change. Breathing is essential to living and so it is to yoga.