How to Create a Custom GPT That Works Like Your Second Brain

There’s a point in every SaaS business where you realize you’re repeating yourself: the same client onboarding responses, the same email templates, the same “can you rewrite this in our tone?” requests. That’s where a custom GPT becomes useful.

A GPT is your own trained assistant that speaks in your voice, understands your rules, and performs tasks the way you want them done.

In this edition, you’ll get a practical, non-technical playbook to create and deploy your own GPT in under a day.

What a GPT Actually Is

A GPT is a private version of ChatGPT that you customize with:

• Instructions – how it should behave and respond

• Knowledge – your documents, SOPs, product manuals, policies, or marketing assets

• Tools or actions – optional: integrations or tasks it can perform

Think of it as a trained team member that never forgets. If you do this right, you stop re-explaining your standards and start saying, “Ask the GPT.”

Step 1 — Define the Job, Not the Tech

Before you touch the builder, answer this question in one sentence:

“What do I want this GPT to do for me every single day?”

Examples:

• “Summarize meeting transcripts into key takeaways and next steps.”

• “Draft client onboarding emails in our company tone.”

• “Generate product documentation based on internal notes.”

This becomes the core instruction set. If you skip it, you’ll build something generic—and you’ll be disappointed.

Action: Write that one-sentence job description. You’ll paste it later.

Step 2 — Create the GPT

Inside ChatGPT, select “Explore GPTs” → “Create a GPT.”

You’ll see two main panels:

• Instructions / Configuration

• Knowledge / Uploaded Files

Here’s what to fill out:

A. Name

Make it functional and clear.
❌ Bad: “AI Helper”
✅ Better: “Marketing Copy Assistant”
✅ Better: “Customer Support Knowledge Bot”

B. Description

Short and outcome-driven.

Example: “You write emails, help center articles, and blog posts in our company’s tone.

You prioritize clarity, brevity, and real-world examples.”

C. Instructions (This is the brain)

This is where you “train” behavior. Paste something like:

Who you are:
“You are my content and communication assistant. You write in a confident, conversational tone that sounds human and helpful.”

Who you’re talking to:
“You’re speaking to SaaS founders, marketers, and operations managers who value clarity and precision.”

How to write:
“Use short sections, clear subheadings, and actionable takeaways. Avoid long intros and unnecessary filler.”

Rules:
“When mentioning our product, focus on measurable outcomes, automation, and simplicity.”

The tighter your instructions, the better your GPT behaves.

Step 3 — Add Knowledge

Your GPT is only as smart as what you feed it.

Upload:

• Internal SOPs

• Product documentation

• Email templates

• Brand voice guide

• Marketing assets

• FAQ documents

• User onboarding scripts

You don’t want it guessing—you want it pulling directly from source.

Example:
If you’re building a “Customer Success GPT,” upload:

• Client onboarding checklists

• Support ticket examples

• FAQ pages

• Tone and style guide

Now, when a team member asks, “How do I respond to a customer requesting a refund?”, the GPT answers using your actual policies.

Tip: Clean your uploads. Remove outdated info or casual notes. The GPT treats everything you upload as truth.

Step 4 — Lock the Voice

This is where your GPT starts sounding like you.

Do this in two ways:

1. Upload approved writing samples — 3–5 examples that sound like your brand:

   • Blog posts

   • Email campaigns

   • Product announcements

2. Tell it what NOT to do.

   • “Do not use corporate jargon.”

   • “Do not sound overly promotional.”

   • “Do not use emojis or exclamation marks unless explicitly asked.”

Your “do not” list keeps it consistent with your brand voice.

Step 5 — Test It with Real Work

Now, put it to the test.
Assign it tasks you actually do daily:

• “Write a follow-up email to a potential partner who didn’t respond.”

• “Summarize this meeting transcript into action items.”

• “Generate a landing page headline about automated reporting.”

If the output doesn’t sound like you, tweak the instructions.

• Too soft? → “Be more confident and concise.”

• Too generic? → “Use real examples, data, or client results.”

• Too long? → “Get to the point within two sentences.”

Tuning is normal. You refine once, and it serves you for months.

Step 6 — Define Boundaries

Teach your GPT what not to answer.

Add these lines:

• “If you’re unsure, ask me to clarify instead of guessing.”

• “If the question involves pricing or legal policies not uploaded, tell me to confirm.”

Boundaries protect your accuracy and credibility.

Step 7 — Share It (Optional)

Once it’s working, you can share your GPT privately with your team.

Use cases:

• Marketing teams: Brand Voice GPT for content creation

• Customer Success: FAQ or SOP GPT for client responses

• Sales: Proposal GPT to ensure consistent messaging

You’re essentially cloning your knowledge and handing it to your team—without extra meetings or training

Key Insights (Quick Reference)

✅ A GPT isn’t “AI for everything” — it’s “AI for one job.”
✅ The instruction block defines 80% of quality.
✅ Feed it only clean, approved data.
✅ Test it against real work.
✅ Done right, it becomes your internal multiplier.

The Bigger Shift

Scaling a SaaS team doesn’t always mean hiring more people.
Sometimes, it means training digital assistants that uphold your standards, write in your voice, and enforce your processes consistently.

Treat your GPT like a team member—with a clear job description, SOPs, and accountability—and it’ll return hours of your time every week.

Hope this helped you see how easy it is to build your own GPT—one that saves time and scales your brain across the business.

‘Til next week,

 Angelo

Would you like a step-by-step guide to writing your Instruction Block so your GPT sounds exactly like you?

👉 Comment “GPT Guide” and I’ll share the fill-in-the-blanks template next week.