Prompt Engineering Guide for Better AI Images
A practical guide to writing clear, controllable prompts that improve image quality and reduce wasted generations.
Good prompts are not long prompts. They are structured prompts.
Prompt structure that scales
A reliable template:
- Subject: who or what is the focus
- Context: where it exists
- Style: visual language and medium
- Camera: framing and lens intent
- Lighting: mood and key light behavior
- Constraints: things to avoid
When prompts fail, one of these blocks is usually ambiguous.
Use specific nouns, not stacked adjectives
Weak: "beautiful, stunning, amazing fantasy scene"
Stronger: "ancient basalt temple carved into sea cliffs, storm clouds, bioluminescent mist"
Concrete nouns reduce model guesswork.
Control negatives deliberately
Negative constraints are most useful when they are narrow:
- avoid extra limbs
- avoid text overlays
- avoid watermark artifacts
Avoid long negative lists unless there is a repeated failure pattern.
Iterate with a changelog mindset
Track each generation attempt with one intentional delta:
- v1 baseline
- v2 changed lens from 35mm to 85mm
- v3 changed lighting from hard noon sun to overcast diffuse
This makes quality improvements reproducible.
Build prompts with tags in Phosphene
Phosphene helps by turning prompt design into composable parts:
- define core subject tags
- layer stylistic tags
- add relation tags to resolve scene logic
The result is faster convergence and fewer "start over" moments.
Final quality check
Before exporting, verify:
- composition reads at thumbnail size
- focal subject is obvious in under one second
- style is consistent across foreground and background
- no artifact immediately breaks immersion
If one fails, revise the specific block instead of rewriting the full prompt.