There seems to be a shortage of simple skills in the workplace these days. I think I struggle the most when I encounter folks who cannot communicate. And when I say cannot communicate, I mean that they lack the basic skills to communicate ideas clearly and completely through either speech or writing.

My most annoyed moments typically occur after receiving and email from a co-worker that suffers from 1 or more of 3 issues.

1. I've been asked to do something, but the email makes no sense
2. I've been asked a question and when I respond I'm told that they already knew the answer and they'll go to someone else for help
3. I reply to an email and no one actually reads it. They somehow guess what I've written and assume things that I never intended or communicated.

So serously, take the time to write emails and documentation that are clear  and also take the time to read emails from co-workers. You may actually learn something. And you may actually not annoy the rest of us all of the time.