Mostly, you don't do it - you let it happen. We've got some amazing teachers guiding you through meditation training and topics. Just find a comfortable position and listen. You can sit, stand, or lie down. Meditation is not about the posture; it's about your intention and attention. If you show up with the intention to simply notice what you're experiencing in the present moment, you are doing it just right.
In the end, peace of mind can't be forced; the practice is more about letting things go, letting things be, and bringing yourself to the present moment.