The essence of writing a cover letter is, this is a letter. You're writing a letter to someone. I think the biggest mistake that people make is they think that this is a form document where they need to very impersonally communicate who they are, and that is not the case. This is a letter between two people. Your first sentence of that letter needs to be about the person who this letter is going to. You need to find out something about them so that in that very first sentence you can say, we know each other by virtue of this connection. I read about you in this particular press release. You need to make this first sentence feel very familiar so that the person on the other end of the letter is actually going to read it. That's the goal of the cover letter. It's to warm them up before they actually dive in to read this resume. Make it short, make it sweet, but definitely make it personal. That's how you write a cover letter.