This is a proven relaxation technique that I use, its not meditation but it redresses the oxygen-cardon dioxide in the body and promotes a feeling of calmness.

Take a deep breath in through your nose for a slow count of four (imagine the air filling your stomach, not lungs, and feel it expand)

Hold for a slow count of four

Breate out through your mouth for a slow count of four (imagine your stomach pushing the air out)

Repeat three or four times (no more)

This works for me, its a proven way to relax, I've got into the habit of doing it when I feel tense.