In a world where you can "friend" someone with the click of a button, face-to-face friendships become even more valuable. In a USA Today editorial, writer Mark Vernon, author of the book "The Meaning of Friendship," notes that social media can actually water down our friendships, even while making us feel that we have more friends. Connecting with a best friend can actually improve your emotional well-being.

1 Care About You A good friend cares about your happiness. She's willing to drop everything to help you when you're in a jam, and she thinks carefully about your feelings before she speaks or acts. Your friend should be focused less on what she is getting out of the friendship and more on what she can give to make the friendship flourish. If she inadvertently hurts you, a best friend feels true regret and tries her best to make it up to you.

2 Inspire You A best friend should help you reach greater personal heights. He should not pull you down, make you feel depressed, or encourage you to do anything detrimental to your health and happiness. Instead, he should inspire you to reach higher. With a best friend, you grow emotionally beyond the person you would have been without him.

3 Share Common Values You may not agree with your best friend on everything; in fact, outwardly agreeing on everything may mean that one of you is unable to share her true self in the relationship. But sharing some core values can help a friendship thrive. Shared values may relate to personal pursuits, spiritual pursuits or ethical issues.

4 Show Empathy Best friends empathize with each other. Your best friend should recognize your feelings -- sometimes without being told -- understand your difficulties and exult in your joys. Your best friend will be almost as excited by your successes as you are, and nearly as upset over your struggles.