Do what I do if you get caught with a judge who wants to talk.
Give short answers and don't ask questions, and keep your eyes on your dog.
Clothes, well it depends on your dog. I wore tracky pants with my border as she didn't like jeans but with my golden it doesn't matter. I tend to wear jeans if the weather is ok, if its wet and muddy I wear tracky pants as they don't hold the rain like the jeans do.
As long as the clothes are clean in the morning (because if your dog is like mine that don't always stay clean) then that's the main thing.