There are too many instances where there's an entire group of people talking and laughing and then there's someone standing to the side awkwardly. More often than not, that person is not choosing to stand there, they want to be a part of the conversation. This behavior is unacceptable and it needs to stop.

You do not have to be best friends with everyone, but you need to treat everyone with the same kindness. Don't claim to be this happy, carefree person who wants to do good if you can't act that way around everyone. You can't say you're against bullying if you're willing to exclude another person, because isolation is the cruelest form of bullying.

It is natural to favor people, but that favoritism should not be obvious. If you're with a group of people, talk to everyone, not just the three people that you relate to. Not every conversation has to be about you, learn about the people around you instead of ignoring them.

Stop looking for people that remind you of yourself. A lot of people think that they can only be friendly towards people that are similar to them, that is not true at all. If you are constantly surrounding yourself with people similar to you/your group of friends, you're missing out on a lot of life lessons.

"Well, they never try to talk to me," is not an excuse anymore. Talk to them. Ask them questions, compliment them, try to make them laugh. You never know how impactful a small conversation can be on another person, especially a person that you do not know very well.

Before you automatically assume you have nothing in common with someone, give them a chance. Your friends don't have to be exactly like you, and you don't have to be friends with every person you meet. Although you don't have to be their best friend, at least act like a friend when you're around them. Let your "weird" co-worker talk your ear off, say "hello" to the person next to you in class, and break away from your "group".