Prompt Engineering for Images

Synopsis

An image prompt is a production brief. It identifies the subject, composition, light, medium, and required or excluded details.

Generated images are drafts. Inspect framing, anatomy, text, repeated objects, factual details, and visual consistency before use.

Write the brief

Build the prompt from concrete fields:

Subject: the main object, person, or scene
Action: what is happening
Setting: place, period, weather, and background
Composition: viewpoint, framing, scale, and placement
Light and color: light source, contrast, and palette
Medium: photograph, ink drawing, flat vector, or another visual form
Constraints: required and prohibited elements
Output: orientation, aspect ratio, and intended use

Do not add descriptors that cannot be checked against the result. Terms such as "modern," "epic," or "professional" leave most visual decisions unspecified.

Describe composition explicitly

Name the visual relationship between important elements.

Bad:

A server room illustration.

Better:

Flat two-color technical illustration of one server rack viewed from the front.
Place the rack in the left third of a landscape frame.
Show three status lights and one network cable.
Use dark blue lines on a warm gray background.
Leave the right half empty for a page title.
No people, text, gradients, reflections, or decorative circuitry.

The revised prompt specifies count, placement, palette, empty space, and exclusions.

Match the medium to the purpose

Use a restrained medium for explanatory images. A simple diagram or editorial illustration usually communicates one concept more clearly than a detailed synthetic scene.

Use photographic terms only when a photographic result is required. Lens length, depth of field, and film references do not improve a flat icon or schematic diagram.

Avoid copying the distinctive style of a living artist. Describe observable properties such as line weight, palette, texture, and composition instead.

Use exclusions carefully

Negative instructions identify likely failure modes. They do not guarantee their absence.

No labels, letters, logos, watermarks, interface chrome, extra cables, or repeated racks.

Keep exclusions specific to the requested image. A long generic list can conflict with positive instructions and make diagnosis difficult.

Revise one variable at a time

Keep the parts that work and name the visible defect.

Keep the rack, palette, and empty right half.
Move the viewpoint to eye level.
Remove the floor reflection.
Do not change the number of status lights.

Changing one group of variables at a time makes the effect of each revision visible. Save the prompt, model name, settings, and selected output when consistency matters.

Check the draft

Inspect each result at full size:

Confirm the subject count and placement
Check hands, faces, cables, wheels, and repeated structures
Read every generated label or replace it with typeset text
Compare symbols, uniforms, maps, and equipment with a reliable reference
Check crops at the final display size
Check contrast in both light and dark page themes
Confirm that the image license and source record permit the intended use

Do not use a plausible image as evidence that a depicted fact is true. Illustrations of technical procedures, medical subjects, people, and historical events require separate factual review.