Using a generative AI tool well gets easier once you understand a few things about how the underlying model actually works, not just how to phrase a prompt.
A model is trained on a large dataset once, at significant computational cost - that's a separate process from "inference," which is what happens every time you generate an output. Nothing you do during normal use changes the underlying trained model.
A model can only consider a limited amount of input at once - your prompt, any reference material, and its own recent output. Long or complex instructions can exceed that limit, which is why breaking a big task into smaller prompts often works better than one giant one.
A short, precise prompt usually outperforms a long, vague one. Models respond to concrete detail - a specific style reference, a specific composition instruction - more reliably than broad adjectives.
Generative models are intentionally non-deterministic - the same prompt can produce different results each time. This is what makes iteration useful: running a prompt again is a legitimate strategy, not a sign something's wrong.