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

Hi Black sheep
I agree with your comment on disliking frozen smiles and artificial gestures.
Unfortunately, these are common because they appear to work! I have seen dancers doing (well rehearsed) goldfish imitations and catching the judges' eyes with them. I am also told that most competition dancers spend time practising facial expressions to go with their steps - i have bewen asked to do this.
Sadly, the aim is to catch the eye of the judge and tricks seem to work - at least they play a part in getting dancers into the finals.
I would LOVE to be able to concentrate on my 'delivery' in a comp (i do ballroom) but it's not as easy as it sounds. I practise and practise but in the comp there is pressure and i can still lose my way and make stupid mistakes. It's very frustrating. Recently we competed using a routine we'd been practising for 3 years. It was a big comp and both of us forgot a whole section of the routine and had to fill in.
If you have any good suggestions on how to relax they'd be very welcome.