Choosing a Pokémon Elite Trainer Box design involves considering personal preferences, card set relevance, and aesthetic appeal. First, look for designs that resonate with your favorite Pokémon or themes. Next, consider the set the box contains; popular expansions may enhance value. Lastly, evaluate limited edition boxes for rarity. Ultimately, choose a design that excites you, as it reflects your passion for collecting and playing the Pokémon Trading Card Game.