I used to be jealous of the popular girls for one reason: they have lots of friends. It didn't took me too long to realise that many of them were fake.. But in all these friends there are also some true friends.
I have two bffs. The chances for them to be true are little. That's the difference.
In my opinion, friendship is when you find a person, a girl or a boy, who has the same interests with you, has the same craze with you, doesn't care if she is seen doing strange things with you, is happy with your success, is sad with your failure, helps you find parts of yourself and wants to do everything with you. She loves you and doesn't want you to get hurt. She protects you. And she tries to do all these things even when she's miles away.
You're not a true friend only when you post selfies of you and your bff with a caption "Forever friends, i don't want to lose you" along with a million hearts, or when you text her "ily" and "".. If you don't mean, don't do it. It will be nonsense.
When she cries over a guy, tell her that you will be with her forever bc it's okay, people are being mean and don't care about your feelings, that she has you and she doesn't need anyone else.
When she's succeeded, tell her that she deserved it and she can do a lot more.
When she falls, grab her hand and ask her if she's okay and make her laugh with a joke.
When she tells you a secret, keep it along with your most hidden secrets.
All these things and a lot more will make her feel better. But it won't be fair if these are done by the one person. It needs effort from both sides.