Some might think that the audio portion of a video takes a backseat to the visual portions, but that’s not true. Most video watchers note that they are more likely to stop watching a video with bad audio vs. lower-quality video. In fact, a recent TechSmith study of video viewing habits showed that more than 25% of video viewers watched a video all the way through because the audio was good — more than those who said professional video style was most important.
Next, go back to the beginning and start editing out your mistakes. I also like to edit out any abnormally long silences between sentences or statements and any weird sounds that don’t belong. Remember, though, that pauses are ok (and even necessary) to help break up the audio and make it feel more natural and conversational, so don’t go hog wild with it.