Techniques

How to write AI image prompts

Good image prompts name the subject, the setting, the lighting, the medium and the framing, in roughly that order, using concrete nouns rather than praise.

The most useful thing to know about prompt writing is that adjectives of quality do almost nothing. Words like "beautiful", "amazing", "masterpiece" and "8k" are so evenly distributed across training data that they carry very little direction. What carries direction is specificity: a named lighting setup, a named medium, a named lens, a named palette. "Soft window light from the left" changes the image; "good lighting" does not.

A structure that reliably works is subject, then action or pose, then setting, then lighting, then medium and style, then framing. Early tokens carry more weight in most models, so lead with what the picture is actually of. "An elderly fisherman mending a net on a harbour wall at dawn, soft directional light, oil painting with visible brushwork, chest up" gives the model six separate hooks, each of which does real work.

Framing and composition are the most under-used part of a prompt. Saying "chest up", "wide establishing shot", "low angle", "centered", or "lots of negative space on the right" gives you control over something that otherwise gets decided randomly, and it is usually the difference between an image you can use and one you cannot. If the picture has a job, whether that is holding a title or fitting a profile circle, say so.

Finally, iterate one variable at a time. Lock the seed, change only the lighting clause, and see what happened. If you rewrite the whole prompt between generations, and the seed changes too, you learn nothing about which change mattered. Most of the skill here is in running controlled experiments rather than in knowing magic words.

In practice

Weak
a beautiful portrait of a fisherman, masterpiece, 8k, highly detailed
Strong
an elderly fisherman mending a net on a harbour wall at dawn, soft directional light from the left, oil painting with visible brushwork, muted earth palette, chest up
Why
Six specific hooks instead of four pieces of praise

Worth remembering

Try it in the generator

The advanced panel exposes the negative prompt, scheduler, inference steps and seed. Twenty images free, no account needed.

Start generating

Frequently asked questions

How long should a prompt be?
Long enough to name subject, setting, lighting, medium and framing, which is usually 20 to 40 words. Beyond that, later terms get progressively less weight, so extra length has diminishing returns.
Do words like 8k and masterpiece help?
Very little. They appear across such a wide range of training images that they barely steer anything. Replace them with a specific medium, lens or lighting description.
Should I name a famous artist?
Avoid naming living artists; it raises real ethical objections and is blocked in many tools. Describing the qualities you want, such as "loose ink linework with watercolour washes", gets you the look without imitating a person.

Related terms

Back to the glossary, or apply it on a use case or an art style.