Since my stutter revolves around my anxiety, I take some measures to be as calm as possible in situations as presentations. What I do is: • Avoid caffeine for a couple of days before • Have a restful night of sleep • Exercise to get that post workout relaxation (might not be possible due to covid right now) • Meditation and breathing exercises • Practicing a lot my presentation • Disclosure my stutter when the presentation starts. This one helps me a lot as it takes some weight out of my shoulders Sorry for my broken english. Hope this helps, you'll do great!