Write out your script. But keep it organic and so the talking points read in the natural flow you would want to sweep through them. This allows you to get ahead of trouble words and plan out verbiage that minimizes distraction where possible or where you can avoid running into problem areas of your speech. Synonyms are your friend… so use them shamelessly. While swapping in words should never be a crutch or avoidance from things you just have to address I.e proper nouns…where there is suddenly word that is just as good USE it. Then work on saying the original word fluently in lower stress environments. Watch the kings speech if you haven’t already seen it. But the movie talks a lot on the prep he does before a big speech. The approach he took in writing out his message beforehand allowed him to adjust content and specific verbiage to what he was more confident saying. Also he breaks up into a pace or rhythm in writing out to help usher his way through when he was giving the actual speech.