I needed seven cover illustrations for this site — four project cards, three essay covers — and they had to look like one family.
The trick that worked: write one frozen prompt skeleton and only swap two variables per image — the subject and the background gradient:
Dreamy soft 3D render, minimal abstract composition: . Smooth glossy surfaces with matte highlights. Background: soft diffuse gradient {the card's own gradient tokens} with gentle blurred color glows. A few tiny four-pointed star sparkles floating. High-key studio lighting, premium playful tech aesthetic, centered composition with generous negative space, no text, no letters, no logos, no people.
Every image inherits the same lighting, material language, and sparkle motif, so the set reads as a system, not a collage. The background clause pulls from the design tokens the card already uses, which is what makes the illustrations feel native to the site instead of pasted on.
Model: gpt-image-2, quality medium — the top tier is not worth 2x the
price for 1200px web covers.