Keep make up and hair simple. Keep your hemline low and your neckline high. Optimal colors for an outfit are jewel tones, or darker colors like navy or gray. Black and white are the two extremes that you should stay away from. Also, pastels can really wash out your coloring.
Jewelry can finish an outfit's look, however keep it simple.
Garish earrings and large, noisy bracelets can distract your audience. Minor or no adjustments will be made for all the others. You will be made to sit there longer and there is a greater chance of your anxiety increasing. Let someone else be the test subject. When it's your turn sit down and knock it out.