Control your nerves. It may feel like you're on show, but don't panic - the audience is focused less on you as a person than on what you're saying. Ignore what's going on in your head and concentrate on the room.
Look up. Avoid relying on your notes. If this means locking yourself away to practise the speech for an hour beforehand, then do so. That leaves you free to engage the audience - and to project, darling, project...
Vary your delivery. Speed up, slow down, emphasise points and add dramatic pauses. Play with the sound - the audience will stay interested, and you'll stay in control.
Don't punish your audience. Everyone's attention span has a limit, and even the most earnest listener will eventually start to shift their weight and plan their supper. Keep it concise, chatty, and drop in laughs where you can.
Keep going. It's OK to make mistakes, so don't get stressed or apologise if you trip over your words. The audience isn't sitting there willing you to fail.
Be yourself. They will warm to you more if they can see you're a real person and that you're enjoying yourself, so make the most of your time in the spotlight. Then volunteer to do it again.