when the new game comes out the only ball i will ever use is going to be the dusk ball, with of course the exception of breeded pokemon and my starter, but besides that, its all dusk ball, even the legends
Random Pokémon that are easy to catch: Great Balls
Random Pokémon that are hard to catch: Repeat Balls
Shinies/rare/important guys: whichever style of Ball that best compliments its looks. The Quick Ball perfectly matches shiny Drifloon, while a Premier Ball's red opening works very well with a pure evil Black Rayquaza.
poke, great, and ultra depending what time in the game it is. i never got into the dusk, heal, nest, ect. balls because they look takki, and not very mighty. It was a stupid idea to make the new-new ones in the first place! Originals over the newbies anyday, even Christmas.