When should I evolve pokemon that do not evolve through levels?

[Lando]

So I have a growlithe, a feebas, and a kirlia. When should I evolve them so they will have the best stats? (kirlia is going to evolve into gallade just saying if it's not obvious)

[randomspot555]

You should evolve them whenever they have learned all the level up moves that they can't learn during their evolution.

Nothing else is really applicable, unless it's a rare case of a more basic form having advantages over it's evolved form (like Pikachu and Raichu).