Something that really bothers me are pointless voicemails. What do I mean by "pointless?"
I will explain: Pointless voicemails are those that go something like, "Hey, it's me - give me a call back." I mean, really?? You don't think that by my seeing your missed call, it's not implied that you want to talk to me? In my opinion, if you don't have something to TELL me that's voicemail-worthy, I'd rather you not leave a message. A missed call is a synonym for "call me back," and it's more likely that I'll return your phone call before listening to your message. Write that down.
For a while, my outgoing message basically told the caller that it was pointless to leave me a message and a text would be better appreciated. However, my roommate told me that's incredibly rude so I changed it. But you know what? It's not rude. What's rude is having someone leaving me a voicemail that says "Hey, call me back." Like, I just wasted time calling my voicemail to listen to what I thought was going to be an urgent message, only to have you ask me to call you back - which is exactly what I would have done as soon as I saw the missed call anyway. My friends all know to leave me a voicemail should there be a story to tell, an anecdote to share, etc. But to say "call me back...." not necessary.
Pointless, I say!
NOTE: This is NOT applicable to any potential future employers.