The difference between an amateur and a professional is simple. An amateur does it when they feel like it, a professional does it when they don’t.
The difference between a good versus an excellent presentation is the amount of rehearsal given to refining and honing the small subtleties that make a significant difference in creating clarity of message.
Whether in front of a mirror or videoing your practice session you will hear and see where subtleties can make a significant difference in how your message is being communicated. A word here, a pause there, a slight gesture delivered, even a facial expression can add or distract from your message. Going live rather than rehearsing is always risky.
Make the time and reap the rewards of adding rehearsal to your speech repertoire.