In any contest, judges will be influenced by the audiance applauses, so it is important that you arrive at least an hour before the contest, and dance in all areas were there are guests. Win the audiance over before the contest begins.
If you dance for the enjoyment, and not to impress, you will come out ahead. The show-offs come off plastic, artifcial.
Save your best moves during the contest for dancing in full view of each judge; if the judge does not see your best moves, they will never know how good you are.
Stay away from the flashy contestants, they distract from you.
If you practice your routines so that you dance without thinking of the steps, then you can concentrate on your delivery, smoothness, fun feeling and stay focused on your partner.
I personally do not like frozen smiles on dancers.
Black Sheep