When you tune your orchestra, make sure your strings are in order, and all their strings are tuned a fifth apart. Also, test your pizz. in your basses, and make sure you can hear them from the audience. Also, make sure the timpani is tuned properly, and your harp glissandos can be heard from a good 50 feet or so.
Your oboe should be able to play long scales, because thats what oboe players like to do.
Tombones like to tune to a Bflat, and not an A like the strings.
And finally when the conductor says its time to go, you have to be ready or they deduct your pay.
Here's a clip of how to tune your orchestra.