Google Gemini Prompting: Best Practices and Use Cases

Gemini is Google's flagship AI — and its biggest superpower isn't the model itself, it's the integration. Gemini lives inside Gmail, Docs, Sheets, Slides, Search, and Android. Knowing how to prompt it well changes how you do daily work, not just how you chat with an AI.

Note: Gemini features and model names change frequently. Check Google's official documentation for current availability.

1. Introduction

Where ChatGPT and Claude are primarily standalone chat tools, Gemini is positioned as a layer that sits on top of everything Google. Open a Google Doc and Gemini can read it. Open Gmail and Gemini can summarise a thread, draft a reply, or pull facts from your inbox. Use Google Search and Gemini can answer with cited live results. This integration changes the prompting style: many of your prompts will reference "this document", "this thread", or "the spreadsheet I just opened".

This tutorial covers how to prompt Gemini effectively in the chat app, inside Workspace, and across Gemini's multimodal capabilities — image, audio, and video understanding.

2. How Gemini Reads Multimodal Input

Gemini is natively multimodal. You can drop in an image, a screenshot, a PDF, an audio clip, or even a short video, and Gemini will analyse it alongside your text prompt. This is the single biggest reason to reach for Gemini over a text-only chatbot.

• Images: describe, transcribe, extract data from charts, identify objects, write alt text.
• PDFs: summarise, extract structured data, answer questions about specific pages.
• Audio: transcribe meetings, summarise voice notes, pull action items from recordings.
• Video: describe contents, extract key moments with timestamps, draft chapter markers.

When you upload media, write a prompt that names what you uploaded and what you want done with it. Gemini handles vague image prompts ("what is this?") fine, but specific prompts produce dramatically better results.

Attached is a screenshot of a quarterly revenue chart
from our investor deck.

Tasks:
1. Extract the numbers into a clean Markdown table:
   columns = Quarter, Revenue (£M), YoY change (%).
2. Highlight the two quarters with the biggest swings.
3. In one paragraph, suggest two possible narratives
   that explain the trend (do not invent specifics).

3. Prompting Gemini Inside Google Workspace

Inside Workspace, Gemini appears as a side panel or inline assistant. The prompts you write here can reference "this email", "this document", or "this sheet" and Gemini will understand. This shifts the prompting style towards short, conversational instructions backed by context Gemini already has.

Draft a reply to this thread.
Tone: warm, professional.
Length: 4–5 sentences.
Confirm the meeting time they suggested, ask for an agenda,
and mention I will bring the Q3 numbers.
Sign off as "Riya".

This sheet contains raw customer feedback in column B.

Add a new column C labelled "Theme" and tag each row
with one of: Pricing, Onboarding, Support, Feature gap, Other.

Then in cell E1, summarise the top 3 themes and their counts.

Gemini in Docs is especially good for first-draft generation when you give it a clear outline, target audience, and length. Gemini in Slides can convert a Doc outline into a starter deck — useful for the structural skeleton, less so for finished design.

4. Live-Web Prompting with Gemini

Gemini can ground its answers in real-time Google Search results. This makes it strong for current events, product comparisons, and any task where freshness matters more than depth. When you want live information, write prompts that explicitly invite citations.

Compare the three most-reviewed wireless ANC headphones
under £250 right now.

For each:
- Model and current street price (UK)
- 2 strengths and 2 weaknesses
- Source link

Then recommend one for a daily commuter who values
comfort over absolute audio fidelity.

Always sanity-check live answers — even with grounding, models can mis-summarise or pick out-of-date pages.

5. The "Gem" Pattern: Reusable Personas

Gemini lets you create Gems — saved personas with a custom system prompt that you can launch instantly. Gems are Gemini's answer to ChatGPT's Custom GPTs. A well-written Gem is the most efficient way to make Gemini fit your everyday workflow.

You are a plain English explainer for a UK financial blog.

Audience: adults aged 30–55 with no finance background.

Rules:
- No jargon. Define unavoidable terms in one short sentence.
- Use short paragraphs (max 3 sentences) and 1 worked example
  per concept.
- UK English (analyse, summarise, behaviour).
- End every explanation with "What to do next" — three short
  practical actions.

Refuse to give specific investment advice. If asked, redirect
to general principles.

6. Patterns That Work Especially Well on Gemini

• Mix media and text in one prompt. Upload a screenshot plus a Google Doc plus your written request — Gemini fuses them well.
• Use it as a Workspace orchestrator. "Read this email, draft a reply, and create a calendar event with the proposed time" works across apps.
• Ask for source links. When Gemini is grounded in Search, requesting citations forces it to anchor claims to real pages.
• Be specific about output target. "Format this for a Google Doc" or "Format this for a Slides bullet list" gets you content that pastes cleanly.
• Lean on its strength with structured data. Tables, CSV-style outputs, and Sheets transformations are where Gemini particularly shines.

7. Practice Exercises

8. Key Takeaways