Good insight and advice Mouthcaller.
jschultz- You need to practice, practice, practice your routine for each call. Don't enter without a routine worked out beforehand. Most contests post the particular calls they will be judging beforehand such as plain yelp, assembly yelp, fly down cackle, cutt'n, purr, kee kee run, etc. etc. Find out what they're going to judge and then develop a routine for each call. Video your routine's. This will be your first contest so have fun with it.
Dan