Here are a few of my tips:
1) Wash bird 5-7 days before the show and keep in a clean pen inside, to allow natural oils to return to the feathers and allow the feathers to settle back down.
2) Apply a little Vaseline on the comb, wattles and feet before judging.
3) Feed and water your bird AFTER...
Try getting them used to being handled little and often, maybe start with 5 minute sessions and gradually build it up every day. After handling the birds, give them a few mealworms (or their other favourite treat) so they associate handling with positive things.