3) Finally, have someone quite young read it to you. Of course, they won't appreciate the argot of your industry. But they can still get better get the gist. Or you're depending on a recruiter to be really familiar with what you do. Also, be concerned about language they can't articulate. We often overrate the literacy in almost any industry.
1) Read it out loud to yourself. Have you missed words? Do you trip over anything? 2) Read it aloud to two or three people who are unfamiliar with your industry. You're looking or understanding and reaction. Ideally, you'll hear _ hey, do you do that? That's how you tell you've gone beyond examples of good cover letters and they're enthusiastic.