Build a “Brand Twin” That Writes Every Post in Your Exact Voice.

The Rundown In this guide, you will learn how to fight back against ChatGPT slop by creating a “Brand Twin”. You will create a custom GPT that writes LinkedIn posts, Instagram captions, etc. And the best part? You won’t have to waste time editing out AI writing that doesn’t match your brand voice. Who This Is Useful For Marketing managers who are tired of rewriting 90% of what AI spits out Content leads who want to scale a specific brand voice across a team Entrepreneurs who don’t know where to start on their brand voice What You Will Build A Custom GPT "Brand Twin" trained on your specific brand kit and "forbidden" word lists. What You Need to Get Started ChatGPT Plus ($20/month) 3-5 samples of your best writing (can be PDFs, markdown or text files) Optional: Brand kit slide deck ( good example ) Step 1 Open a new ChatGPT thread in the phone or desktop app. Upload 3-5 examples of your best writing + your brand kit if you have one. Tell it: “Analyze these uploads to extract my brand's 'DNA' for a Custom GPT System Prompt. Identify the specific voice posture, sentence cadence, and vocabulary preferences, while creating a strict 'Forbidden List' of corporate cliches and AI-isms to avoid. Specifically, define syntactic constraints—such as banning em-dashes or 'not just A, but also B' structures—to ensure the output never reverts to generic AI slop.” Step 2 Navigate to  https://chatgpt.com/gpts  in your web browser, click “Create” in the top right. Name your GPT and paste in the system instructions you generated in step 1 Upload your writing samples and brand kit. You can keep everything else default 💡Pro tip: We used Liquid Death as our example brand because their brand voice is unique and recognizable. Here’s an old version of their  brand kit  that you can use to template your own. Step 3 Now click  Share > GPT Store . ****Open the ChatGPT desktop app and click  GPTs > Explore GPTs > Search Public GPTs. Find your GPT and click “Start Chat”. Click the  name at the top > Pin GPT Going Further To test your new GPT out, try putting the same prompt in your brand twin and in a temporary ChatGPT thread. You can use this test to refine your system instructions. If you have a teammate writing copy for your brand, have them add this GPT and ask it to “grade” how well the copy fits your brand voice 1-10. This way they will level up their writing skills instead of just mindlessly copying and pasting.

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