How to stop my face from blushing, i go blushed whenever i need to present in front of a crowd. how to overcome the anxiety?

How to overcome the anxiety when presenting to public:

1. Well prepare your material of presentation or speech in advance.
2. For the first couple minutes of your presentation, treat the crowd as a single object (死物) and don't focus your eyes on them for their reaction. That means, you may look at somewhere else when you start the introduction.
3. Take a deep breath. If you're still nervous, continue speaking without focusing on the crowd.
4. When you feel confident, start looking at a single person one at a time, imagining this person as your good friend.
5. You will feel relaxed if you think you are talking to only a single person who is one of your friends or family members.
6. Move on to look at different persons from time to time, especilly those with convincing looks.