Relax and breathe
As a retired competitor and instructor of Brazilian jiu-jitsu, one of the most important lessons I learned, as well as taught, was stated in 3 words: relax and breathe!
As a matter of fact, anyone training in jiu-jitsu, has heard that phrase repeated countless times. The reason is that proper breathing plays an integral role in learning how to deal with stress in a self-defense and/or athletic situation.
Now, as a preacher, I'm thankful for the lessons I've learned in how to relax and breathe properly because proper breathing is also vitally important when speaking in public.
Proper breathing helps with articulation and projection. It's helps with vocal range. It helps a speaker relax and not appear to be nervous, even if he is.
Breathing properly also provides protection from straining your voice.
I've heard that a lot of speakers hire a vocal coach, and I'm sure the training they provide is helpful and valuable.
However, the focus on proper breathing that is emphasized in jiu-jitsu may be an unorthodox way to help preachers with their breath control.
So after you get prayed up, and before you preach your next sermon, remember to RELAX and BREATHE!