5 common AI prompt mistakes ruining your interior design renders

Getting great AI-generated interiors starts with the right prompts. But many designers struggle because of common mistakes that ruin their visuals. In this article, I’ll share the top prompt errors I see for Midjourney and how to fix them, so you can create stunning AI interiors that impress clients and speed up your workflow.

Mistake #1: Too vague or generic prompts

When prompts are too broad or generic, AI can generate visuals that lack focus or specific style. Saying “modern living room” without details often results in generic images that don’t stand out.

Example: To get better results, add descriptive details about style, colors, materials, lighting, and mood. Instead of “modern living room,” try “modern living room with warm wood accents, soft natural light, and minimalist Scandinavian furniture.”

Mistake #2: Too many conflicting ideas

Sometimes we get carried away and try to include too many styles or design directions in a single prompt. When that happens, MidJourney tries to blend everything — and the results often look confused or incoherent.

Example: If you’re saying things like “a brutalist, Scandinavian, Art Deco, modular home with minimalist Japanese interiors...”, it’s just too much. Those styles don’t naturally fit together, and you’re likely to end up with visual noise instead of a clear image.

A better approach is to choose one clear direction. You can still explore other styles, but do it in separate prompts. That way, you get cleaner outputs, and you can actually compare what works best.

Mistake #3: Focusing on what you don’t want

This is a big one — using too many negative instructions like "no clutter," "not modern," or "no people." The more time you spend telling the AI what not to do, the less clear it becomes on what it should do.

Example: Instead of writing “a modern home, no clutter, not industrial,” try focusing on what you actually want to see: “a modern home with clean surfaces, minimalist furniture, neutral color palette, and soft natural light.”

You’re much more likely to get the results you want by staying positive and specific. If you really need to exclude something, you can use the --no parameter, but use it sparingly — and always at the end of your prompt.

Mistake #4: Placing parameters in the wrong spot

This is more of a technical mistake, but it matters. Parameters like --ar, --style, --no, or --sref need to be placed at the end of your prompt. If you drop them into the middle, MidJourney might ignore them or misinterpret the whole thing.

Let’s say you want a 16:9 image ratio.

Example: This is incorrect: “Modern villa --ar 16:9 with pool and pergola.” This is correct: “Modern villa with pool and pergola --ar 16:9.” Always write your descriptive prompt first, then tack on the parameters at the end, separated by spaces.

Mistake #5: Ignoring the style or mood

AI thrives on style and mood cues. Forgetting to specify these can lead to bland or inconsistent renders that don’t evoke the intended atmosphere. Always include adjectives that describe light quality, color schemes, material textures, and emotional tone.

Example: “Cozy, warm lighting with soft shadows and natural wood textures” will give a very different feel than “bright, cool lighting with sleek metallic surfaces.”

I once helped a student struggling with flat renders. After adding mood descriptors like “golden hour sunlight” and “velvet upholstery,” their AI images transformed into rich, inviting scenes that wowed their clients.

Conclusion

Mastering the art of prompting in Midjourney is key to unlocking the full potential of AI in interior design. Avoid these common mistakes to create visuals that truly reflect your creative vision and impress your clients.

If you want to dive deeper, learn practical prompt techniques, and boost your AI rendering skills, check out my AI course for interior designers.