This simple yogic breathing exercise from Natural Health, Natural Medicine by Dr. Andrew Weil is a great natural tranquilizer.
Practice this exercise often (2 times a day) so that it will work effectively for you when you need it!
When learning the exercise, sit with your back straight. Once it’s learned, you can do the exercise in any position.
Place the tip of your tongue against the ridge of tissue just behind your upper front teeth, and keep it there through the entire exercise. Breathe in the following way:
Exhale completely through your mouth, making a whoosh sound.
Close your mouth and inhale through your nose to the mental count of 4.
Hold your breath for a count of 7.
Exhale completely through your mouth, making a whoosh sound to the count of 8.
Now inhale again and repeat the cycle 3 more times for a total of 4 breaths. (Do not do more than 4 breaths at one time for the 1st month of practice. Later, you can extend it to 8 breaths, if you wish.)