Final answer:
Using a one-size-fits-all approach is not effective for working with diverse client populations. Instead, methods like cultural competence training, building trust and respect, and adapting communication styles are recommended.
Step-by-step explanation:
The method that is not a way of increasing effectiveness in working with diverse client populations is using a one-size-fits-all approach. Such an approach overlooks the unique cultural, social, and personal backgrounds of different clients, which is counterproductive to fostering understanding and effectiveness in diverse settings. On the contrary, effective strategies include cultural competence training, building relationships based on trust and respect, and adapting communication styles to meet the needs of different client populations. These methods promote an individualized approach that respects and values the diversity of clients by seeking to understand their cultural contexts, developing trustful relationships, and communicating in ways that are most likely to be effective and respectful.