How to Write Social Media Posts with AI: From Brief to Published

By Infinithink Studio · October 24, 2026

Most social posts start as a text message from the owner. "We're doing a free flat-tire clinic on the 14th, can you post it?" If you write social media posts with AI by pasting that line into a chat window and asking for "a post," you get something generic, with no sign-up details and the same wording on every network.

A better approach is a short social media content workflow, where each step has one job and one tool. Below is a seven-tool workflow in Infinithink, from a two-line brief to posts ready to schedule, with one example business carried through every step.

The example brief

This is an illustrative example. Say a neighborhood bike shop in Columbus, Ohio, which we'll call Elm Street Bikes, wants to promote a free workshop. The owner sends this.

"Free flat-tire clinic Saturday Nov 14, 10 to noon at the shop. Max 12 people. Can you post it everywhere?"

Before any tool runs, check the brief against five questions. What is happening, when, where, who it is for, and what people should do next. Here the last two are missing. One reply from the owner fills the gap. The clinic is for commuters and anyone with a bike sitting in the garage, people should bring their own bike, and they sign up at the counter or through a form on the website.

This step matters more than any prompt. The tools work only from the facts you give them, so a missing detail stays missing everywhere, or shows up as a placeholder like [link].

The seven-tool social media content workflow

Here is the whole flow at a glance. Every writing tool in the table works on the Free plan.

How to write social media posts with AI, step by step

Step 1: one update, four networks

Open Business Post for Social Media. Enter the company name exactly as it should appear, then the full update with date, time, place, conditions and the action you want.

"Free flat-tire clinic at Elm Street Bikes on Saturday, November 14, from 10 a.m. to noon. For commuters and anyone with a bike stuck in the garage. Bring your own bike, we'll show you how to fix a flat yourself. Limited to 12 people. Sign up at the counter or at [link]."

You get four posts with the same facts. Facebook gets a conversational post of 40 to 80 words, Instagram short lines and up to five hashtags, LinkedIn 80 to 150 words, and X a single idea in 280 characters or fewer. A Facebook version might read like this.

"Got a bike in the garage with a flat tire? Bring it in. On Saturday, November 14, from 10 a.m. to noon, we're running a free flat-tire clinic at Elm Street Bikes. You'll fix the flat yourself, with us right next to you. Spots are limited to 12, so sign up at the counter or at [link]. When did you last ride it?"

The output ends with one suggested visual for all four posts, such as a close-up of hands on a tire lever. Keep it for step 5.

Step 2: the first line

The first line decides whether anyone reads the rest. Hooks for Posts and Videos writes fifteen openers in five styles, from curiosity to a direct question, each 15 words or fewer, and picks three to test first. Describe the content, who it is for and the main point. For the clinic, options like these could come back.

"A flat tire is a ten-minute fix once someone shows you."

"When did your bike last leave the garage?"

"Twelve spots, one Saturday morning, zero flat tires on the way home."

Every hook has to be delivered by the content, so the tool is built not to promise results the post cannot back up. Pick the line that sounds like the shop. It becomes the opening of the Instagram caption and, if you shoot a Reel, the on-screen text in the first seconds. One caution from our own example: "a ten-minute fix" is a claim. If the owner would not stand behind it, cut it.

Step 3: the Instagram caption

The Instagram version from step 1 is fine for a single photo. For a carousel, say a tire lever, a patched tube and the shop counter, use Instagram Captions. Describe what the slides show, who you are talking to and the action you want, here signing up through the link in bio. You get Short, Medium and Long captions. The medium one suits a carousel.

"When did your bike last leave the garage?

Bring it to our free flat-tire clinic. You'll do the fix, we'll walk you through it.

Saturday, November 14, 10 a.m. to noon. 12 spots.

Sign up through the link in bio."

We swapped in the chosen hook as the first line by hand. The tool does not see your photos. It writes from your description, so describe what is actually in the frame.

Step 4: five hashtags, not thirty

At the time of writing, Instagram allows at most five hashtags per post or Reel, according to the platform. Instagram Hashtags returns three sets of five, one for the niche, one for the wider community and one for place, season or event, plus a reserve list of ten. For a local shop, the place set usually reaches the right people. One possible set is #ColumbusOhio #ColumbusCycling #BikeCommuter #BikeRepair #FlatTireFix.

Watch one detail. Both the step 1 Instagram post and the caption already end with hashtags. If you use a set from the generator, replace those tags rather than adding to them, or you go over the limit. The tool does not see live Instagram data, so search any tag you do not recognize before you use it.

Step 5: the image

If you have a good real photo of the shop, use it. The Image Generator is for when you do not, and you need a scene. Write the prompt as a short scene description, not a keyword list, and pick the size, 1024x1024 for a square feed post or 1024x1536 for a vertical story.

"Realistic photo of hands using a blue tire lever on a bicycle wheel on a wooden workbench, small bike shop in the background, soft morning light, close-up, no faces, no text, empty space at the top."

We asked for no text and no logos on purpose. Generated images often get small details wrong, letters included, and prompts should not imitate real brands. Add the date in the empty space yourself. A generated image is a mood shot, never a stand-in for a photo of the actual shop.

Step 6: the owner's LinkedIn post

The LinkedIn version from step 1 speaks for the business and fits the company page. On the owner's personal profile, a first-person post works better. LinkedIn Post writes one from rough notes, with a hook under 200 characters, short paragraphs, a genuine closing question and three to five hashtags. The detail that makes it personal belongs in the notes, for example "half the bikes we see in spring just need a new tube, and people pay for a repair they could do in the driveway." The tool is built to use only the facts you give it, without adding numbers or quotes, and you still check the result.

Step 7: proofread last

By now you have edited almost everything by hand, which is exactly where errors creep in. Say the owner adds a line to the caption, "Bring you're bike, its free." Proofreading returns the full corrected text and a numbered list of changes with the reason for each.

"1. you're → your, possessive, not a contraction of you are.

2. its → it's, contraction of it is."

The tool fixes errors, it does not rewrite, and it cannot check facts. A correctly spelled Saturday, November 15 is still wrong, so the fact check is yours.

Before you schedule

None of these tools publish or schedule anything. Before you paste each version into your network or scheduler, run one last check.

• Date, time and number of spots match in every post.
• No placeholders left, such as [link] or [date].
• Five hashtags or fewer on Instagram.
• Every hook is backed up by the post.
• The image has no garbled text or odd details.

Mistakes that cost the most

Generating from an incomplete brief. Two vague lines produce four vague posts. One follow-up question to the client fixes more than any amount of editing later.

Cramming two announcements into one run. The clinic and a winter tune-up sale in the same update give you posts that try to say too much. Run them separately.

Relative dates. "This Saturday" ages badly in a scheduled post. Always write the exact date.

What it costs

The writing tools above all work on the Free plan, which is free and needs no credit card, and unused credits stay as long as the account is active. For text, credits are used based on the words the AI writes, and a full run of this workflow takes at least six text generations and one image. If you post every week or handle several clients, paid plans give you more credits and add Brand Voice, which saves your business's tone so it stays consistent from one post to the next. The pricing page shows which plans include it.

Start free with the Free plan. No credit card and no time limit, and the writing tools are ready to use right away. Create your free account

Frequently asked questions

Can I write social media posts with AI for free?

Yes. Every writing tool in this workflow works on the Free plan, with no credit card and no time limit.

Which tools do I need if I only post on Instagram?

Instagram Captions, Instagram Hashtags and, if you have no photo, the Image Generator. Hooks for Posts and Videos helps with the first line, and Proofreading closes the job.

Do these tools publish posts for me?

No. They write the text and create the image. Publishing and scheduling stay with you, in the network or the scheduling tool you already use.

How do I keep AI-written posts from sounding generic?

Put one real detail in the brief, rewrite the first line by hand if it does not sound like you, and read the post out loud. On paid plans, Brand Voice keeps your tone consistent across posts.