If you drive a lot, you could consider recording the talk (just read it into your smartphone, for example) and then playing it back on low volume, while you try to speak just ahead of it. Then try again with the speed accelerated (most phones can do this). One of TED’s favorite speaker coaches, Gina Barnett, believes the key is to be able to recite the talk at double speed. When you can do that comfortably, giving the talk at normal speed will be automatic and you can focus 100 percent on meaning.
