AI Masterclass: How to develop your own CustomGPT prompt

The real problem

You use ChatGPT, Claude or Gemini regularly - but the results are different every time.

Sometimes the AI writes too superficially.
Sometimes too technical.
Sometimes it misses your target completely.

The cause is almost always the same:

You're working without a clear system prompt.

Many companies are experimenting with AI, but they have no structured prompts, no defined roles and no reproducible results.

The result:

• Teams lose time
• Results are inconsistent
• Knowledge remains in the heads of individuals
• AI is not scalable

The solution is obvious:

CustomGPT prompts.

Why the problem persists

In practice, we observe three typical mistakes.

1. ad hoc prompting

Most users write spontaneous prompts like:

"Write me a blog article about AI."

This leads to generic results.

The reason:
AI knows no role, no goal, no format, no target group.

2. tool focus instead of system thinking

Many teams think:

"We need the right AI tool."

But the real problem is usually

The prompt.

A good prompt can turn a normal model into an extremely powerful assistant.

3. no standardization

In companies, it often looks like this:

• Marketing uses ChatGPT
• HR uses Claude
• Product uses Gemini

But everyone works completely differently.

There is:

• no prompt structure
• no templates
• no role models

This means that AI remains an experiment instead of a system.

The concrete solution: The CustomGPT Prompt Framework

A stable CustomGPT prompt always consists of five building blocks.

The 5-block prompt framework

1️⃣ Role

Who is the AI?

Example:

You are an experienced AI consultant with a strong practical focus.

2️⃣ Target group

Who are you working for?

Example:

You write for entrepreneurs and decision-makers who want to use AI in practice.

3️⃣ Goal

What do you want to achieve?

Example:

The aim is to provide practical, actionable content.

4️⃣ Structure

How should the answer be structured?

Example:

• Problem
• Solution
• Example: Solution
• Implementation steps

5️⃣ Style

How should it be written?

Example:

• clear
• practical
• comprehensible
• no theory

The result:

The AI works like a specialized employee.

How to create a CustomGPT prompt - step by step

The three major models differ slightly here.

1️⃣ Create CustomGPT with ChatGPT

ChatGPT currently offers the simplest solution for custom prompts.

You can create your own GPTs directly in the interface.

The process:

Step 1

Open:

Explore GPTs → Create

Step 2

Define the system role.

Example:

You are an AI consultant for medium-sized companies and explain in a practical way how AI is implemented.

Step 3

Define the rules.

For example:

• always write in a structured way
• use examples
• avoid technical jargon
• provide concrete implementation steps

Step 4

Optional: Add knowledge

You can upload:

• PDFs
• guides
• internal documents
• best practices

This turns your GPT into a company assistant.

Result

You get:

your own GPT with your own personality.

Perfect for:

• Marketing
• support
• knowledge management
• internal training

2️⃣ Custom prompts with Anthropic Claude

Claude works a little differently.

Here you work more with long system prompts.

The structure looks like this:

Example Claude Custom Prompt

You are an experienced business consultant for AI strategy.

Your job is to help companies to
introduce AI in a structured way.

You always work according to the following pattern:

1. analyze the problem
2. explain the causes
3. develop a concrete solution
4. provide a practical example
5. define implementation steps

Style rules:

- clear
- practice-oriented
- comprehensible
- No academic language

Advantage of Claude

Claude is particularly strong in:

• long contexts
• complex analyses
• strategy development
• document work

Many companies use Claude for:

• strategy
• Concept development
• research

3️⃣ Custom prompts with Google Gemini

Gemini is often customized via Gemini Gems or AI Studio

The process:

Step 1

Create a Gem (Custom Assistant).

Step 2

Define:

• Role
• Goal
• Task area

Example:

You are an AI implementation consultant for SMEs.

Step 3

Define areas of responsibility:

• Recognize automation potential
• Analyze processes
• Identify AI agents

Special feature of Gemini

Gemini is particularly strong in:

• Google Workspace Integration
• data analysis
• research
• Multimodality

This makes it particularly interesting for companies that already work heavily with Google tools .

Practical example

A medium-sized consulting company wanted to use AI in marketing.

Previously

Marketing wrote prompts like:

"Write a LinkedIn post about AI."

Result:

• generic
• interchangeable
• no brand style

Solution

The company developed a Marketing CustomGPT prompt.

The prompt defined:

• Role: B2B marketing strategist
• Target group: Managing director
• Style: clear, practical
• Structure: Hook → Problem → Insight → Solution

After

Results:

• Consistent content
• higher reach
• 80% faster production

The real difference was not the model.

The difference was the prompt.

Immediately actionable steps

If you want to build your own CustomGPT prompts, start with these five steps.

1️⃣ Define a clear role

Examples:

• AI consultant
• Marketing strategist
• Sales coach
• product manager

2️⃣ Define target group

Examples:

• Medium-sized companies
• Marketing teams
• HR departments
• SaaS companies

3️⃣ Define a fixed structure

For example:

• Problem
• Analysis
• Solution
• Implementation

4️⃣ Define style rules

Examples:

• practical
• understandable
• no empty phrases
• concrete examples

5️⃣ Save your prompts

Create a prompt library

Typical categories:

• Content
• analysis
• strategy
• automation
• Agent building

This will create an AI work infrastructure in the long term.

Strategic classification

Companies that use AI successfully do one thing differently:

Theydon't just use AI as a tool.

They build systems.

This includes

• Prompt libraries
• CustomGPTs
• AI agents
• Automations

Companies without these structures will only everuse AI superficially.

Companies with these structures create

• faster processes
• better decisions
• scalable knowledge work

The decisive lever is often surprisingly simple:

The prompt.

Conclusion

The biggest difference between average and excellent AI usage is rarely the model.

Whether youwork with ChatGPT, Claude or Gemini plays a smaller role than many people think.

The real lever is:

A cleanly developed custom prompt.

It transforms a general model into:

• a marketing expert
• a strategy consultant
• a process analyst
• a content creator

And that's where the real AI transformation begins.

🚀 Next step

If you not only want to understand AI, but also use it in a structured way in your company, then:

👉 Find out more about our AI training:
https://bloo.school

👉 Find out about our Smart Market Fit offers:
https://bloola.com/smf - The Smart Market Fit course
https://bloola.com/smf-system - The Smart Market Fit system for companies

👉 Or find out more about our consulting and automation solutions:
https://bloola.com