Where Do AI Instructions Actually Belong in Your Workflow?
Between custom instructions, projects, and Custom GPTs, there are now multiple ways to “train the bot”… but they all work a little differently. And unless you know what goes where, things can get messy fast.
So let’s break it down.
In this post, I’ll walk you through what each type of instruction is actually good for - so you can stop guessing, streamline your workflow, and start using ChatGPT like the assistant you wish you had.
ChatGPT Custom Instructions
Your default setting for how AI talks to you and understands you.
This is the part most people skip - but it’s what makes ChatGPT actually feel like it gets you.
Think of Custom Instructions as your baseline. You tell ChatGPT:
What it should know about you (your biz, your vibe, your audience)
How you want it to respond (short, cozy, to the point; short and sassy)
Once set, these instructions apply to all new chats - so you’re not re-explaining your tone or audience every time you open a thread.
Best used for:
Everyday brainstorming
Misc writing tasks
Getting responses in your voice
Quick ideas, validation, and convos that don’t need a full setup
It’s not built for complex systems or multi-step projects. But it is the reason ChatGPT knows your tone, your audience, and your style from the jump.
Projects
Structured, repeatable workflows for the things you do often.
If Custom Instructions are your foundation, Projects are your containers. They’re a way to group related chats, hold task-specific instructions, upload relevant files, and stay organized without starting from scratch every time.
Think of them like folders - each one has its own goal or theme, but still pulls in your global ChatGPT instructions in the background.
So if you’ve already trained ChatGPT to write in your brand voice? You don’t need to repeat it here. Just focus the Project on the task itself - what you want it to do, not how it should sound.
Best used for:
Writing Instagram posts with the same structure each time
Outlining and drafting blog posts
Running launch prep using a repeatable system
Any process where you reuse the same steps or format
You can add task-specific instructions and upload any files you want the project to have on hand. Those instructions stay steady across chats - until you change them. Once you revise them, any new chat in that project will automatically use the updated version.
You only have to set the workflow rules once. From there, it’s a rinse-and-repeat system that keeps you from reinventing the wheel every time.
Custom GPTs
Reusable, role-based assistants you can train once and use forever.
If ChatGPT with custom instructions is your default assistant, and Projects are your repeatable systems, then Custom GPTs are your specialist hires.
They’re purpose-built AI sidekicks that you can train for one specific role, give clear boundaries, and reuse over and over again. You can even upload files, include links, add examples, and give them a job title. And the best part? Once they’re trained, you don’t have to explain yourself again.
Best used for:
Turning long-form content into repurposed Instagram posts
Acting as a community manager that replies in your brand voice
Editing or rewriting your work in a consistent tone
Running client work or coaching prompts that follow the same method every time
Building a shareable GPT for collaborators, clients, or team members
Unlike Projects, Custom GPTs don’t live inside your general ChatGPT dashboard - they’re standalone. But they’re powerful. They remember their job. They stay in role. And they don’t need hand-holding.
Need to tweak something? Just update the instructions or files and it’s done.
This is your AI working for you - on brand, on task, and on call.
Not Sure What to Use? Here’s the Quick Breakdown:
ChatGPT Custom Instructions
Use when you want consistent tone, voice, and response style across all chats.
Best for:
Everyday brainstorming
Writing support in your voice
Quick tasks without needing a full setup
Projects
Use when you’re doing structured, repeatable work - and want a place to keep task-specific instructions and files.
Best for:
Instagram content workflows
Blog post outlines and drafts
Launch prep systems and templates
Custom GPTs
Use when you need a specialized assistant trained to do one job really well.
Best for:
Content repurposing sidekicks
Personal editors or brand voice guardians
Custom tools you can share with clients or collaborators
These tools aren’t interchangeable—they work best together.
Set your tone with Custom Instructions.
Build your systems with Projects.
Assign roles with Custom GPTs.
That’s the stack.
That’s how you make AI feel like part of your team.
Final Thoughts
Most people aren’t using these tools to their full potential - because no one ever explains where the instructions are supposed to go. But now you know.
You don’t need a complicated setup. You just need the right instructions in the right places.
Use your custom instructions to make ChatGPT sound like you.
Use projects to stay organized and run your go-to systems.
Use custom GPTs to create AI sidekicks that don’t need retraining.
Start small. Stack smart. Let your AI carry some of the weight.
Want the cheat sheet version of this post?
Download my free guide: “Get Your Instructions Straight”—it breaks down each tool, when to use it, and how to set it up fast.