What's the meaning of “walk through it before you run with it”?
Write it out. It’s helpful to write out your elevator speech in a long version at first, then take a tip from President Ronald Reagan and transfer your core outline and key points and phrases to an index card. Recite the long version first, and then recite it from the cards to work on your word selection and phrasing. I often tell my clients to “walk through it before you run with it.” Eventually, you will not need any notes at all!