The difficulty of prompt engineering cannot be underestimated. You have to try lots of variations and iterate heaps on the prompt. I usually generate several hundred images to pick from and evaluate based on connection to the topic, coherence + esthetic.

For many generated images, people don't have a specific target in mind and let themselves be surprised (which is fun!), but it's quite difficult to take a given topic, write a prompt and get back a coherent image that is on topic.