I had a great adviser when I did this in 2002.
Practice speaking out loud over and over again. Not just muttering in front of your PPT slides on your laptop sitting on the couch, but actually stand up and look at yourself in the mirror and present. The cadence of telling a verbal story can really inform where you might need more slides or less slides, or where you need visual transition slides. You should know your talking points and keywords you want to hit, but don’t write a speech. Learn to read an audience and present to people who are engaged and look enthusiastic.