top of page
Search

How I Use Nano Banana (Gemini Image) for Clean, Controlled Image Generation

  • Writer: JOYAL JOHNSON
    JOYAL JOHNSON
  • Jan 3
  • 2 min read

Nano Banana (Gemini Image) is my go-to when I want fast image generation with tight control. I don’t prompt it casually — I prompt it like I’m briefing a designer and a camera crew at the same time.


The goal: clean visuals, consistent outputs, and avoiding that “obvious AI” look.




The rules I always follow


1) Always mention the platform


I start every prompt by stating where I’m generating the image, so my workflow stays consistent and prompts are reusable.

Examples:

  • Platform: Gemini (Web/App)

  • Platform: Google AI Studio (Nano Banana / Gemini Image)



2) Always set exact dimensions

I never say “Instagram size.” I write the numbers.

Common sizes:

  • 1080×1350 (IG post)

  • 1080×1920 (Story/Reel cover)

  • 1920×1080 (landscape / YouTube)

  • 2048×2048 (square)

  • 3840×2160 (4K)



3) Use negative prompts every time


Negative prompting is non-negotiable. It prevents random artifacts, clutter, and the model “freestyling” things you didn’t ask for.


My usual “avoid” list includes:

  • oversaturated colors, neon grading, heavy HDR

  • plastic/waxy texture, uncanny faces

  • extra fingers/warped anatomy

  • cluttered backgrounds and random objects

  • glowing edges, oversharpening, artifacts

  • watermarks/logos

  • (for posters) warped or gibberish text



4) Avoid the usual “AI” color tone


If you don’t control the color grade, you’ll often get that default AI look: too punchy, too glossy, too perfect.

So I specify:

  • neutral whites

  • slightly muted saturation

  • natural skin tones

  • no HDR / no teal-orange overload

  • subtle grain / realistic texture


5) I describe the technical side like a real shoot


This is where the quality jumps. I explicitly define the image like it’s a camera shot:

  • Subject (what matters)

  • Focus (what must be sharp)

  • Depth of field (shallow bokeh vs deep focus)

  • Foreground / background (what exists, what’s blurred)

  • Lighting (soft daylight, studio, cinematic low-key, etc.)

  • Composition (center, rule of thirds, negative space)

  • Color tone (neutral, warm, cool, muted)



That keeps Nano Banana from guessing the aesthetic.



My iteration method: “keep everything the same”


After the first output, I don’t rewrite the whole prompt. I iterate like an editor:

  • “Keep everything the same, change only the background to ___.”

  • “Keep composition and lighting identical, reduce saturation by ~20%.”

  • “Keep subject the same, make it more muted and realistic.”

  • “Keep layout the same, increase whitespace and move headline higher.”


That keeps consistency and prevents the model from reinventing the entire design.


Quick recap: my Nano Banana checklist

Before I generate anything, I make sure my prompt includes:

  • ✅ Platform

  • ✅ Exact dimensions

  • ✅ Technical image details (subject, focus, DoF, lighting, color tone, background/foreground)

  • ✅ Negative prompts

  • ✅ Poster typography/layout rules (when relevant)

  • ✅ Iteration instruction (“keep everything the same, change only…”)



Summary


Nano Banana is fast — but the real difference is how you prompt it. When you control platform + dimensions + technical details + negative prompts, you get outputs that look intentional, not “AI default.”


If you want, drop one image idea (photo or poster) and the platform + dimensions, and I’ll write a ready-to-run Nano Banana prompt in this exact format.

Comments

bottom of page