Post a weekly or even daily (if you’re unemployed you have the time) tip about your professional experiences.
You have more knowledge in your head than you realize.
A classic interview question is when the interviewer asks you to describe a specific challenge you’ve had and describe how you over came it.
Your first post should answer one important question.. “Why?”
Why do you want to work?
Why do you want to work in your chosen profession.
Why do you want to revolutionize your field?
Actually each of those questions can be a different post.