I tend to go with pant suits or skirt suits in contrasting colors to the dogs. Going the suit route helps you look more professional IMO. My fave suits for the Belgians for big shows are...white :O
Still sometimes I feel like having casual Friday, Saturday or Sunday at a show. On those days, l'll wear khakis and a nice colorful top. And if it's really hot, sometimes just a skirt and nice tank top. If it's really wet or muddy, I go with a skirt cause suit pants in light colors don't hold up so well to mud.