I judged these at the AR a few years back. Great fun!
I think the best approach is to relax and remember that there are no rules or targets for sides or sauces. Call up your best memories of great examples and look at why you thought they were good. Open up your mind and tastebuds and savor the opportunity. Work without preconception of what an item "should be" and maximize your experience of "what it is". In this kind of competition, entries with broad appeal will tend to do well while highly specialized or "niche" items (I once encountered a curry flavored sauce) don't fare as well.
You'll likely be using the standard 3-score system: Appearance/taste/tenderness. Usually, the lead rep will help you redefine the tenderness category to a broader concept like "texture" or pleasant mouth feel.
Enjoy
Hub