Lesson 02 · ChatGPT Mastery Pro ~16 min read 3 GPT builds

Custom GPTs: build your first in 20 min.

Custom GPTs are ChatGPT's most underused power feature. Every Plus subscriber can build their own — a purpose-built assistant with custom instructions, conversation starters, knowledge files, and even tool integrations. Most users have never made one. This lesson walks 3 real builds: a sales follow-up GPT, a meeting prep GPT, and an executive summary GPT.

The mental model

Custom GPTs are reusable instructions you build once.

Instead of re-prompting Claude with the same setup every time, you bake the setup into a GPT. Open the GPT, type a short query, get high-quality output that matches the patterns you defined. The 20-minute investment compounds across every future use.

Workflow 01 Build a Sales Follow-Up GPT

1

GPT: "Sales Follow-Up Pro"

A GPT that drafts follow-up emails using the specific-friction pattern and your tone.

The prompt that works

Setup walkthroughChatGPT → Explore GPTs → Create → Name: 'Sales Follow-Up Pro' → Instructions: 'You draft sales follow-up emails. Always ask first: what happened in the prior interaction, what specific detail or friction can I reference, what's the ask. Then draft. Under 80 words, friendly but not desperate, no clichés.' → Conversation starters: 'Draft a follow-up to a ghosted prospect' / 'Help me ask for a renewal'

Best use cases

  • B2B sales reps
  • Account managers
  • Anyone doing customer-facing outreach
  • Founders writing customer emails
Don't put real customer names or deal details in the GPT instructions — they're stored. Keep instructions about process; keep specifics in the conversation.
Time savings: Re-explaining the email pattern: gone forever.

Workflow 02 Build a Meeting Prep GPT

2

GPT: "Meeting Prep"

A GPT that helps you walk into any meeting prepared. Tell it who/what, get a brief.

The prompt that works

Setup walkthroughCreate → 'Meeting Prep' → Instructions: 'When given a meeting topic and attendees, produce: (1) 3-bullet context summary, (2) the 3 most likely outcomes to push for, (3) the 2 most likely objections to prepare for, (4) one good opening question.' → Starters: 'Help me prep for a 1:1' / 'I have a customer meeting in 30 min'

Best use cases

  • Anyone with back-to-back meetings
  • Sales reps prepping for calls
  • Managers prepping for 1:1s and reviews
  • Founders prepping for investor or partner meetings
The GPT can't know specifics about your company or contacts unless you tell it in the prompt. Keep a doc of context to paste in.
Time savings: 10 min of meeting prep → 2 min.

Workflow 03 Build an Executive Summary GPT

3

GPT: "Exec Summary"

A GPT that turns long content into ruthless executive summaries that respect a CFO's attention.

The prompt that works

Setup walkthroughCreate → 'Exec Summary' → Instructions: 'When given any content, produce: (1) one-sentence TLDR, (2) three bullet points of what matters, (3) one bullet of what to do about it. No fluff, no "this comprehensive report explores" garbage. Direct, executive voice.' → Starters: 'Summarize this report' / 'Compress this thread'

Best use cases

  • Anyone who has to forward info to time-poor executives
  • Investor updates
  • Internal team briefings
  • Long-meeting recap summaries
Test the output against a 30-second CEO read. If they couldn't act on it without reading more, the summary failed.
Time savings: Re-drafting summaries to fit attention spans: gone.

Final challenge: build the one GPT that pays off

Pick the workflow you do most often in ChatGPT. Build a Custom GPT for it in 20 minutes. Use it for the next week instead of regular ChatGPT. Most users find the quality jump immediate.

Back to ChatGPT Mastery → See pricing →

What you can do now

  • Build a Custom GPT in under 20 minutes with the 4 essential fields (name, instructions, starters, capabilities)
  • Write instructions that constrain output without paralyzing the model
  • Decide what to keep in instructions (process) vs. what to put in each conversation (specifics)
  • Test a GPT against real use cases before deploying it widely
  • Recognize when to update vs. create-new for an evolving workflow
Pro
Up next in ChatGPT Mastery

Lesson 3 · Canvas: the editing surface that changes how you write

When to invoke Canvas (and when it gets in the way), inline editing, version control, collaborative writing patterns. The feature that turns ChatGPT into a real writing partner. See pricing →