Public Speaking tip of the day: never practice your speech in front of a mirror.
I know what you must be thinking: but people give this advice all the time! Well, it is awful advice! The fact of the matter is that when you speak in a mirror, you tend to get distracted easily. It is human nature to examine themselves whenever they see their reflection: you begin to think that your nose is crooked or that your hairline looked much better a decade ago than it does right now.
That is not what you want to focus on. You want to focus on an audience member. You should never ever give a speech without rehearsal. But your rehearsal should not be in front of a mirror. Instead, record yourself on your cell phone camera and just focus on speaking. Then when you are watching the recording, just focus on that.
That is one of the problems with mirrors, you are trying to watch and speak at the same time. So do not practice in front of a mirror; practice on video.