One of the most effective ways to cope with anxiety is deep breathing. Deep breaths get much-needed oxygen to your brain and throughout your body, relaxing your muscles. The increased air to your body and mind helps you calm down in times when you would normally become stressed out.
When you notice that you're beginning to get nervous, pay attention to your breathing. For a few days, practice deep breathing in a relaxed, private, comfortable environment where you're not rushed. Put your hand on your belly, and make your hand rise and fall with each breath. Be sure to take in a slow, full breath. Exhale slowly.
If you practice this deep breathing exercise before the moment of truth, you'll be equipped to control your breathing when a stressful situation occurs. When the pressure is on, and you notice your heartbeat beginning to rise, simply pay attention to your breathing and do what you've practiced.