>>31406843I use PKHeX to edit my mons with a very specific set of IVs: I make then in order to be 31, 26, 21, 16, 11 and 6. 31 Being the highest base stat on the fully evolved form of the given Pokémon, and 6 being the lowest. In case of a tie, I decide with stat is going to be higher based on the Pokémon. I also edit the nature to boost the highest stat and reduce the lowest.
For exemple, let's say I'm using A-Ninetales, which has 73 Hp/67 Atk/75 Def/81 Sp. Atk/100 Sp. Def/109 Spe, it's IVs would be: 31 Spe, 26 Sp. Def, 21 Sp. Atk, 16 Def, 11 Hp, 6 Atk, and it would have a Timid nature.
I only use those in-game, not online.