Don't act like I'm the only one who ever gets an awkward look when I say something in a conversation.  We all say things that are taken out of context, am I not correct?  I'm pretty sure you or me have used almost every single one of these!

Don’t say: “You look tired.”

Why: It implies she doesn’t look good.

Instead say: “Is everything OK?” We often blurt the “tired” comment when we get the sense that the other person feels out of sorts. So just ask.

(via 18 Common Phrases to Avoid in Conversation | Real Simple.)