I try to slowly pronounce the alphabet before every presentation or high pressure speech, and I found articulating every single syllable in a word that is tripping me up helps too! I also caress my arm or leg to get me through an entire word like “micro data auditing” (mi-cro-dah-tah-aw-dit-ing). I don’t know if it’ll help for others, but this definitely helps for me :) I did my master’s thesis presentation using this method with some great practice everyday.