how do you know if youre doing breathing techniques properly?

My therapist has been helping me learn relaxation breathing techniques. When I'm at her office with her and relaxed and she's showing me how to do them I can do them just fine. When I'm in the midst of a panic attack I have a hard time doing the techniques because I'm so scared and hyperventilating. I try and take deep breaths but I'm not sure that I'm doing them right, like the belly breathing. When I'm in the midst of an attack how can I know if I'm doing the techniques right? I can never take in as long of a breath that I'm supposed to. Not sure if its from the hyperventilation or because I smoke. Does it really matter that I don't do them exactly right?

This is all new to me. I've never used natural techniques to get over panic attacks so I'm still learning.

[JGF25]

The whole point in the breathing techniques is to bring your heart rate back down so that you will be able to get out of the panic attack.  I think the only way you could be doing it wrong is if you were not holding the breath long enough.  If you take a breath in and hold it, even if it is a shallow breath, then you cannot possibly continue to hyperventilate.  Did your therapist tell you to put your hands on your stomach so that you would feel it rise and fall with each breath and to count to say 5 while you were holding your breath?  Both of these things help to distract you as well.  To be honest with you, sometimes I take in a breath and hold it like I was underwater in a pool and then let it out especially if I feel a panic attack coming on.  I immediately start breathing and I can usually stop it from continuing.  

So don't worry about how you are doing it per se.  The key is to take the breath in, hold it  for 5 seconds, and then let it out.    

Hopefully this helps Erin.