Here are some guides for the strategy in Pokémon video games, in the 6th and 7th gens (X/Y, ORAS and Sun/Moon versions). It's a little-known game aspect but who is interesting to play.
This tutorial for the strategy in Pokémon teach you how to construct the most effective strategic team possible step-by-step, in a simple way.
This tutorial for the strategy in Pokémon teach you how to breed correctly your Pokémon (in a Pokémon pension) to maximize their strategic potential, all this explained in a simple way