Most people spend far too much time on writing their speech and not enough time practising it. Now, for a few people that's fine as they speak better when it's spontaneous. They are often confident speakers and know their material well. They represent about 3% of people. They are not you and me.
We need to practise. We need heaps of practice or it will not be alright on the day. How many times? Most people practise three times. It's not nearly enough. I suggest you practise 13 times, AS IF.
As if means as if you are in front of the people you are actually going to speak in front of. If you do not know them, imagine them. It will make you a little more nervous when you do this. However, on the day, you will have been there "speaking" to them 13 times. Believe me, you will look and sound confident.
Now, some people practise in front of the mirror. They are braver than me. All I see is the Purple lady who has put on weight! You do not even have to say it aloud. You can run through the whole thing in your head. However, most people practise the first half more than the second and it shows on the day. The most important parts to have off by heart are the beginning and the end, especially the end. It is the last thing you say, the most memorable and should be said the loudest and most powerfully.
Please do not finish with "Thank you." It's very polite and nice, but not memorable.