A mentor pastor once gave me the valuable lesson of assigning me to listen to recordings of my own sermons. I did not want to do it. I found that I did not like the sound of my own voice on a recording, but despite the pain of listening to myself I learned a lot about delivery. I learned my voice sounds better when I properly breathe and project. I learned that in order to sound as dramatic as my thoughts, I really need to increase my vocal inflections; while I may feel like an exaggerating bad actor, the congregations perceives me as simply passionate.
My church now records sermons in HD video for our satellite campus, St. Criox Valley Wesleyan Church, and I see audio recordings more like seeing but a poor reflection as in a mirror, but now I see face to face, in high-definition! I have had my sermons video recorded in the past, but sometimes got mediocre camera work, or I had months to prepare for the recording. To be able to examine my delivery every week benefits me and my listeners, provided I do something about what I see.
There are, of course, other mirrors we should regularly look into . . .
Anyone who listens to the word but does not do what it says is like a man who looks at his face in a mirror and, after looking at himself, goes away and immediately forgets what he looks like. But the man who looks intently into the perfect law that gives freedom, and continues to do this, not forgetting what he has heard, but doing it–he will be blessed in what he does. James 1:23-25