From vague prompts to reliable AI assistants
TS&E Team • 9 December 2025
Every time you use ChatGPT, you start from zero. You explain your context, your preferences, your constraints—again and again.
"Write an email to the hotel about our team offsite booking."
"Dear Sir/Madam, I hope this email finds you well. I am writing to enquire about..."
❌ Wrong tone. Missing details. Doesn't know your policies.
A Custom GPT is ChatGPT pre-configured with your instructions, knowledge, and personality. It remembers how you work so you don't have to repeat yourself.
Knows your policies, tone, and preferences from the start
Same quality and format every time, for everyone
Upload documents it can reference—guides, policies, FAQs
Define who it is and how it behaves
Let ChatGPT help improve your prompt
Upload documents it should reference
Refine based on real usage
Who is this GPT? What expertise does it have? Be specific about its identity.
How should it respond? What tone? What format? What should it never do?
Show it what good output looks like. Few-shot examples dramatically improve quality.
Modern models follow instructions precisely. Vague prompts get vague results.
# ROLE You are the Supercell Travel Assistant, helping the admin team draft booking emails and answer travel policy questions. # BEHAVIOUR - Always check travel policy before answering - Use friendly but professional tone - Format emails ready to send - Ask clarifying questions if details missing # CONSTRAINTS - Never approve expenses outside policy - Always include booking reference numbers - Flag trips needing lead approval # EXAMPLE OUTPUT Subject: Booking Request - [Name] to Helsinki Hi [Hotel Contact], We'd like to book...
Meta-prompting means using ChatGPT to improve your prompts. Instead of guessing, ask the AI to help you write better instructions.
Write a basic version of your system prompt—it doesn't need to be perfect.
Paste your prompt into ChatGPT and ask it to improve it.
"Review this system prompt and make it more
effective. Ask me clarifying questions to improve
it."
Answer its questions, test the improved version, repeat until satisfied.
Pro tip: Quality beats quantity. A small, clean FAQ document will outperform a massive policy dump. Structure your knowledge as "Question → Answer" pairs for best results.
Test the exact use case you designed it for
Try unusual inputs and unexpected questions
Check it refuses things outside its scope
Ask the same thing multiple times
Test → Find issues → Update prompt → Repeat
Generates ready-to-send emails for hotel and flight bookings based on trip details.
# ROLE You are the Supercell Travel Booking Assistant. You help admin staff draft booking request emails for business trips. # YOUR TASK When given trip details, generate a ready-to-send email to the appropriate contact (hotel or airline). # INPUT FORMAT You'll receive: traveller name, dates, destinations, hotel preferences, and business purpose. # OUTPUT FORMAT Generate an email with: - Clear subject line with traveller name and dates - Professional but friendly greeting - All trip details in organised format - Any special requests (dietary, accessibility) - Sign-off ready for admin to send # KNOWLEDGE TO REFERENCE - Check travel-policy.pdf for spending limits - Use hotel-contacts.csv for email addresses - Reference airline-preferences.md for carriers # CONSTRAINTS - Flag any trips exceeding policy limits - Always ask for lead approval status - Include booking reference if provided - Never send emails automatically—draft only # EXAMPLE Input: "Sumin to Helsinki, 9-16 Jan, Lapland Hotel" Output: Subject: Booking Request - Sumin Choo, 9-16 Jan HEL Hi [Hotel Contact], We'd like to request a booking: - Guest: Sumin Choo - Check-in: 9 January 2026 - Check-out: 16 January 2026 - Room type: Standard single Please confirm availability and rate. Best regards, [Admin Name]
You already have great use cases. Here's how they map to Custom GPTs:
GPT trained on office policies, onboarding guides, and FAQs. Answers questions using your actual documentation.
Interactive GPT that walks new hires through checklists, explains policies, and answers setup questions.
Takes trip requests and generates booking emails with correct contacts and policy compliance.
Ideation partner with knowledge of venues, activities, and past offsites. Proposes full itineraries.
Reviews copy and ensures it matches Supercell's communication style—no corporate jargon.
Quick lookup of dietary requirements from team data for event planning.
Choose the simplest, most repetitive task from your list. Start small.
Write a basic system prompt. Use meta-prompting to improve it. Test it.
Show your GPT to the team. Get feedback. Iterate together.
Let's discuss your specific use cases and how to build GPTs that actually help your work.
help.openai.com/custom-gpts
promptingguide.ai