Can anyone give me some pointers on persuasive writing to get new customers?

I've been posting in a few Facebook groups lately as I never get much traction from ads and it seems to be a better, easier way to reach the audience I need. Do you have any tips for writing a small post that sells me well and makes people want to reach out. I am good at listing facts and pointers but not really the persuasive side. I want people to read it and want to book a service with me. Thank you!