If I could give you just one tip to improve your day-to-day writing, it would be this: give yourself permission to write badly.
Bad writing, you see, can be fixed. That’s how we get to good writing – we write badly, and then we craft it till it’s good. A blank page, however, is no use to anyone.
So start – just start. No one is expecting you to be the Steinbeck of Sales, or the Hemingway of Human Resources. It’s just a memo, Mabel.
Write a draft, take a short break from it, and then make it better – that’s all you need to do.