What helps me a lot, I write the full speech I’m gonna present and time it. I try to practice it alone then when I get confident enough I present it to extremely small audiences (1 to 3 people). I think getting to know the presentation helps lowering the stress so the stutter doesn’t worsen. For the actual presentation, just be confident. You’ve got amazing things to present and you know your subject very well. If you stutter, that’s okay. I started having good presentations (mostly) after I embraced the stutter. What breaks it for me though, are the weird looks on some people when I stutter once or twice (or more). So I try to only make eye contact with people I’m familiar with.