Word-of-mouth leads in Tucson after 7 years as a teaching assistant

Two small Tucson employers told me they are hiring but have not posted yet. There are 7 people counting on me, so I am trying to be careful. 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.