Most sound work in films is done very quickly, and at the end of the schedule where it's just jammed together and you always wish that you had more sympathy.
Ben BurttI've always found that when you're trying to create illusions with sound, especially in a science fiction or fantasy movie, that pulling sounds from the world around us is a great way to cement that illusion because you can go out and record an elevator in George Lucas's house or something, and it will have that motor sound.
Ben Burtt