Being a better friend than you think you need to be may sound obvious.
But I think there's a deeper and more subtle reason to do this, and once you know it, the idea takes on a new meaning.
The logic is rooted in the idea that most people want to avoid confrontation. If your friend does something annoying, chances are you'll deal with it instead of confronting your friend. If your friend is reprehensible, you may just stop being friends with them rather than have a difficult conversation with them to work through all the issues.
You're probably unaware of many rude and annoying things that you are doing to friends. Chances are good that they can just deal with it because they're still your friends.
So be a better friend than you think you have to be and try to balance out the bad with overwhelming good because you may never know all of the bad you're doing.