Before now and then, make sure you practice your speed/time/distance calculations. The ones you will get on the day are relatively easy, but you absolutely need to be fluent in them, as they will be fired at you.
You need to be able to do them in your sleep!!
When you are in front of the officers, remember that they are looking for leadership; they want to see how persuasive and determined you are - but at the same time it is not a competition with your fellow board members!
Oh, and keep calm.......don't panic!