GOOD LUCK!
Some of the things you have heard are correct but still there lots of chances you will make it.

1.Take your light breakfast if its in the AM.
Wear something comfortable including your rubber shoes.
2.Greet the officer or the examiner.
3.Take a deep breath and do some stetching before the test
3.Don't panic, presence of mind and be confident.
4.Constant practice will make you comfortable and free from mistakes.
5.And if you made a small mistake during the exam, try
not to show it.
6.After the exam, thank the examiner.

Hope this will help.