Prompt engineering is often taught as a technical hack. It is more useful to think of it as creative direction, the same skill an art director uses with a photographer, applied to a model instead of a person.
Subject, treatment, intent
Strong prompts name the subject, the treatment and the intent. Weak prompts name only the subject and then complain that the result is generic.
Iteration is the work
Treat the first 30 images as research, not output. The actual craft is in the editing, what you reject, what you push further and what you finally finish.