We all run into those situations where we feel obligated to say something to get past the awkwardness of a conversation, and even when we get the conversation going, there are certain things you should just really avoid saying or doing.

To the person who wears makeup

What you say: "I think you're prettier/handsomer without make-up."
What they hear: "You just wasted all that time in front of the mirror for nothing!"

That's great, really. But people who wear makeup will probably think you're lying and also wouldn't really take it as a compliment. Do you know how long it takes to apply makeup to look the certain way that someone wants to look like? For some people, it's upwards of an hour; for others, it can only take five minutes. But to be told that you would've looked better if you hadn't just spent however long you did in front of the mirror highlighting your favorite features of your face, yeah—not really a compliment.

To your single friends

What you say: "How are you still single?"
What they hear: "Is there something wrong with you?"

Again, this is one of those "meant as a compliment but really isn't one" things. You probably meant it well, but people who are complaining about being single really don't want to be reminded of it. Think of it this way, when you act surprised at the thought of your friend being single, you're insinuating at there's something wrong with being single, and everything right about being in a relationship. Not so great now.

To the friend who needs someone to listen

What you say: "I don't care"
What they hear: "Leave me alone, what you have to say isn't important enough."

Now this isn't the "I don't care" that you respond with when someone asks you what you want for dinner, it's the "I don't care" you respond with when someone's actually talking to you. Yeah, maybe they talk too much or blabber on about their feelings, but you should never insinuate that you're too busy to take the time to listen to them. There are other ways of getting across to them that you don't want to listen or don't have the time at the moment.

To the person who needs a little extra help

What you say: "This should be easy!"
What they hear: "Everyone is able to do this but you. You're just not smart/agile/good enough!"

By implying that something that someone might need a little help with is supposed to be easy, you're making them feel like it has to be easy for them too or else they're just not good enough. Level of difficulty varies from person to person and everyone has different ways of doing things, so give them time and never tell them something should be easy for them even when it's clearly not.

To yourself

What you say: "I'm not good enough."

You might really think that, but it's probably not true. If you continue to try and do whatever it is that you think you're not good enough for, you might really surprise yourself. Never tell yourself that you're not good enough for something. You're undervaluing who you are and what you're capable of. Take the time to improve what you might not be great at and blow the world away. Life is about taking chances and exceeding the expectations you set for yourself, not about exceeding those set by others. Believe in who you are and life might just surprise you.