AI workflow5 min read
The UI prompt pack: six prompts against generic AI UI
Copy-paste prompts I use with Claude to get production-grade UI instead of the default AI look: taste constraints, polish passes, teardowns, palettes.
With no constraints, an AI tool returns the competent, forgettable default: decorative gradients, a three-column card grid, a violet accent. These six prompts are the constraints I paste into Claude to force taste into the result. Use them as is, then tune the numbers to your brand.
The same constraints, as skills
The prompts still work alone, pasted into any chat. Their rules now also ship as installable skills, which the agent loads when a task matches and which run checks a prompt cannot: a direction gate before any code, and a detector for 20 tells of generated UI. The Design bundle, with the skills CLI:
npx skills add molveau/skills -s anti-slop -s ui -s ux -s motion -s design-grill -s design-inspiration-indexIn Claude Code, all eleven skills as one plugin:
/plugin marketplace add molveau/skills
/plugin install molveau-skills@molveauEvery skill is on the skills page, and the source is on GitHub. How they compare with unslop, taste-skill and Impeccable is in the anti-slop skills comparison.
1. The taste contract
Paste this once at the start of any UI session. It removes most of the generic look, and its first rule makes the agent commit to a direction before it writes code, so the result does not slide into the next default.
You are building UI under these non-negotiable constraints:
- Direction: before any code for a new screen, write five lines and
wait for my approval. Product (what, for whom), character (two or
three concrete words, never clean, modern, sleek, minimal or premium),
world (the place or material it belongs to), moments (the one or two
places that get rich color and detail), signature (one detail only
this product has).
- Typography: max 65 characters per line of body text. Two font families
maximum. Bold for emphasis, never italic. Underline only for links.
- Color: one background family, one ink color, at most one accent.
Text contrast must meet WCAG AA. Never convey state with color alone.
- Motion: animate only transform and opacity. Everything under 300ms,
ease-out on entry. Frequent actions get no animation at all.
Honor prefers-reduced-motion.
- Layout: one focal point per screen. Spacing in multiples of 4px.
- Interactive elements: press feedback (scale 0.96 on active),
44px minimum touch targets, visible keyboard focus.
Reject any of my requests that would violate these rules, and say why.2. The anti-generic pass
Run it after a first draft. Each of its five rules targets one AI default.
Review the interface you just built and remove the "AI default" look:
1. Replace any gradient used as decoration with a flat surface.
2. Replace the accent color if it is violet, indigo, or teal, and do not
swap it for the next default: a cream page with a terracotta, burnt
orange or sage accent, or a single blue accent on white.
3. Remove every card border-plus-shadow combo; pick one, not both.
4. Remove any icon that merely repeats the label next to it.
5. Rework any section that is a 3-column grid of icon-title-text cards,
and any first screen that is only a centred eyebrow, a headline and
two buttons.
Explain each change in one line. Then apply them.The second half of rule 2 matters. Once violet is banned, models reach for cream and terracotta, which is now as common as the gradient it replaced.
3. The polish pass
Run it on each component before it ships, for the last 10 percent a first build skips.
Do a polish pass on this component. Check and fix:
- Alignment: every element sits on the spacing grid, no off-by-2px gaps.
- Truncation: long text truncates with a real ellipsis, nothing overflows.
- States: hover, focus-visible, active, disabled and loading are all styled.
- Empty and error states exist and are written in plain language.
- Numbers use tabular figures if they can change while visible.
List what you fixed. Do not add features.4. The teardown
Point it at a site you admire, or at your own.
Tear down this interface like a senior design engineer. Grade it on:
typography (line length, scale, families), hierarchy (focal points,
spacing rhythm), color (palette size, contrast), motion (duration,
properties animated, reduced-motion), and trust (contact path, legal,
dead links). For each: pass or fail, one sentence of evidence, and the
single cheapest fix. End with the three fixes with the highest
impact-to-effort ratio.5. The palette builder
Use it when the brand has one color and you need a full system.
Build a UI palette from this brand color: [hex]. Produce:
- A near-neutral background pair (light surface + card surface),
tinted toward the brand's world rather than a default cream.
- An ink color for text that is not pure black.
- Muted text, border, and disabled variants of the ink.
- The brand color reserved for primary actions and focus only.
Give every color as a CSS custom property, verify AA contrast for
each text/background pair, and show the failing pairs if any.6. The motion spec
Asking for "some animation" is how interfaces get worse. This prompt makes each animation justify itself first.
Propose motion for this component with this constraint: the best
animation is often none. For each candidate animation state which user
question it answers (where did this come from? what just changed?).
If it answers none, cut it. For the survivors: property animated
(transform/opacity only), duration under 300ms, easing, and the
reduced-motion fallback. Output as a table.How to use the pack
| Prompt | When |
|---|---|
| 1 | at the start of every session |
| 2 and 3 | after every meaningful chunk of UI |
| 4 to 6 | when the situation calls for them |
Do not ask the AI for taste. Give it yours as constraints, and keep the last line of prompt 1 so it enforces them against your own requests too.
These are the prompts I use on client sites. If you would rather hand off your own site than generate it, the studio prices are public.
Stanislas Molveau
Founder, Molveau Studio
I design and build web and mobile products, and write these guides from teardowns of real apps rather than theory.