Word-of-mouth leads in Austin - any advice?

A friend who works at a local manufacturer says there are openings not advertised online. I do not usually post, so bear with me. One is a print shop, one is an accounting firm and one is a clinic. What do you write in a cold email?

Visiting in person worked for a trades job. For office jobs, email was better.

Keep a list of who you contacted and when. It makes follow-ups easy.