In the Pokémon series starting with Ruby and Sapphire, you get stars placed on your Trainer Card for reaching certain milestones in the game, such as Pokédex completion and entering the Hall of Fame. For the past few generations they have been denoted by background colors and, in (Ultra) Sun and Moon, stamps, but stars return in Sword and Shield. Unlike past games, though, they seem to be more easily obtained. Like the past games, of course, it's not exactly clear what the criteria is to get each star. I have all of the stars so far, but I'm curious as to what the exact criteria is to get them.
What milestones must be reached to get each of the stars on your League Card in Pokémon Sword and Shield?