Prompting best practices (gpt-image-1.5)

Structure

Use a consistent order: scene/background -> subject -> key details -> constraints -> output intent.
Include intended use (ad, UI mock, infographic) to set the mode and polish level.
For complex requests, use short labeled lines instead of a long paragraph.

Name materials, textures, and visual medium (photo, watercolor, 3D render).
For photorealism, include camera/composition language (lens, framing, lighting).
Add targeted quality cues only when needed (film grain, textured brushstrokes, macro detail); avoid generic "8K" style prompts.

Don’t use vibe-only buzzwords (“epic”, “cinematic”, “trending”, “8k”, “award-winning”, “unreal engine”, “artstation”) unless the user explicitly wants that look.
Specify restraint: “minimal”, “editorial”, “premium”, “subtle”, “natural color grading”, “soft contrast”, “no harsh bloom”, “no oversharpening”.
For 3D/illustration, name the finish you want: “matte”, “paper grain”, “ink texture”, “flat color with soft shadow”; avoid “glossy plastic” unless requested.
Add a short negative line when needed (especially for marketing art): “Avoid: stock-photo vibe; cheesy lens flare; oversaturated neon; excessive bokeh; fake-looking smiles; clutter”.

Specify framing and viewpoint (close-up, wide, top-down) and placement ("logo top-right").
Call out negative space if you need room for UI or overlays.

State what must not change ("keep background unchanged").
For edits, say "change only X; keep Y unchanged" and repeat invariants on every iteration to reduce drift.

Put literal text in quotes or ALL CAPS and specify typography (font style, size, color, placement).
Spell uncommon words letter-by-letter if accuracy matters.
For in-image copy, require verbatim rendering and no extra characters.

For latency-sensitive runs, start at quality=low and only raise it if needed.
Use quality=high for text-heavy or detail-critical images.
For strict edits (identity preservation, layout lock), consider input_fidelity=high.

Generate:

photorealistic-natural: Prompt as if a real photo is captured in the moment; use photography language (lens, lighting, framing); call for real texture (pores, wrinkles, fabric wear, imperfections); avoid studio polish or staging; use quality=high when detail matters.
product-mockup: Describe the product/packaging and materials; ensure clean silhouette and label clarity; if in-image text is needed, require verbatim rendering and specify typography.
ui-mockup: Describe a real product; focus on layout, hierarchy, and common UI elements; avoid concept-art language so it looks shippable.
infographic-diagram: Define the audience and layout flow; label parts explicitly; require verbatim text; use quality=high.
logo-brand: Keep it simple and scalable; ask for a strong silhouette and balanced negative space; avoid gradients and fine detail.
illustration-story: Define panels or scene beats; keep each action concrete; for continuity, restate character traits and outfit each time.
stylized-concept: Specify style cues, material finish, and rendering approach (3D, painterly, clay); add a short "Avoid" line to prevent tacky effects.
historical-scene: State the location/date and required period accuracy; constrain clothing, props, and environment to match the era.

Edit:

text-localization: Change only the text; preserve layout, typography, spacing, and hierarchy; no extra words or reflow unless needed.
identity-preserve: Lock identity (face, body, pose, hair, expression); change only the specified elements; match lighting and shadows; use input_fidelity=high if likeness drifts.
precise-object-edit: Specify exactly what to remove/replace; preserve surrounding texture and lighting; keep everything else unchanged.
lighting-weather: Change only environmental conditions (light, shadows, atmosphere, precipitation); keep geometry, framing, and subject identity.
background-extraction: Request transparent background; crisp silhouette; no halos; preserve label text exactly; optionally add a subtle contact shadow.
style-transfer: Specify style cues to preserve (palette, texture, brushwork) and what must change; add "no extra elements" to prevent drift.
compositing: Reference inputs by index; specify what moves where; match lighting, perspective, and scale; keep background and framing unchanged.
sketch-to-render: Preserve layout, proportions, and perspective; add plausible materials, lighting, and environment; "do not add new elements or text."

For copy/paste prompt specs (examples only), see references/sample-prompts.md. This file focuses on principles, structure, and iteration patterns.