For example, I'm constantly running into trainers who are in a different stance than normal in the beginning of battles. They also throw the PokeBalls differently. So, how do I change my stance?
You go to Malie City, pass the library and go up that road to find a guy next to the waste station. He will let you change your battling style.
I think after beating the kahunas, you can go to their houses and they will give a you a battle stance. Then the guy from Malie city lets you change it.