Kundalini Yoga Meditation:
For this meditation. Sit up straight and bring your hands into namaste pose, keeping a small gap between the thumbs and keep the palms slightly cupped. Then inhale deeply and blow out gently aiming at the gap between your thumbs, thus allowing the cool air to fill the region between your palms and circulate there. Keep your eyes 1/10th open looking down during this meditation and keep you mind on your breath and the cool sensation when blowing into your palms.
This meditation is sure to relax you rapidly. Continue to do it for 3 minutes.
Breath Awareness Meditation:
This is probably the most used technique for generating quick relaxation and this was the technique used in the studies which measured the reduction of stress hormones as well.
For this meditation, simply sit up straight, close your eyes and bring your attention to your breathing. If thoughts arise, just see them as thoughts only and let them go without getting involved, and return your attention to your breath. Continue this simple method for 3 minutes. It will greatly calm your mind and relax all your energies.