Content from real work.
FROM A COMPLETED JOB
"I completed this today: [what the problem was, what I did]. Write a caption for [platform]. Conversational. A few relevant local hashtags."
FROM A PRODUCT
"I am selling [product]. Details: [specifications and price]. Write a caption. Include how to order."
FROM A CUSTOMER QUESTION
"A customer asked me [question] today. My answer was [answer]. Write a post sharing this, as something useful."
That format works well. It demonstrates competence without selling.
ANNOUNCING SOMETHING
"We are [announcement]. Write a short post. Plain, no hype."
FOR A SERIES
"Here are five common problems customers have with [thing]. Write five short posts, one per problem, each with the practical answer."
ADAPTING ACROSS PLATFORMS
"Adapt this for [other platform], where the audience is [describe]."
WHAT MATTERS MORE THAN THE CAPTION
The photograph, and that the work is real.