Changing voice

Hi! Now that I am practicing recording for the audio submission due at the end of this month, I am noticing when I listen to my voice recordings that I would to have my voice sound less whiny and nasal. I don’t hear that quality in Brooke or Jody or Bev, for example. I am wondering if you are aware of any “tried and true” practices for changing the habits I have that lead to these qualities, or if it’s just as good to google it. 🙂
Thank you!