If you are capable of doing so, try to avoid verbal fillers, especially "you know" and "umm". Ideally, you pause and let the audience catch up. It is a lot harder to do this in practice, especially if you are not practiced with public speaking (Toastmasters is excellent for this).

Nervousness can make people speak faster. Don't worry about getting through all of your slides, if you have slides. It's not a race to the Q&A slide. Confidence can be projected by speaking assuredly.

If you don't have a podium, avoid jamming your hands in your pockets. That feels and looks awkward. Try simply just hanging your arms at your side, relaxed, bringing your hands up when you want to gesture.

If there is a room in which you are speaking, stand near the entrance and shake people's hands as they enter. This is a simple trick to make yourself less nervous if you are not as comfortable speaking to strangers as you are to people who you know. The idea here is that by shaking hands, you've already "met" some of the audience.

Finally, don't be afraid to share your mistakes and failures and even make a joke about them. Failure makes you relatable to the audience.