In the last few weeks I've had some experiences where things worked out great for me because I was honest, up front and understanding with other people. It can sometimes be a really hard thing to do, especially when you get caught in the cognitive bias trap that just reinforces how you are right and the other person is wrong.
Most of the time, you're wrong. If someone is upset with you, then it's probably not because they're a moron, it's probably because you're wrong about something. That friend who won't let you borrow $5 to cover the rest of your overdue phone bill probably isn't being a Scrooge just because they feel like it. Maybe just last week someone you don't know borrowed money from them, and they're having trouble getting it back? Maybe it was you, and you don't even remember?
To you, the friend is wrong because of your situation with the phone bill. In that situation, it's easy to be blinded by the reasons the friend is wrong and not see any reason why you might be wrong.
How do you make sure you're not blinded by cognitive bias?
Maybe you could spend all your time second guessing everything you do to make sure you aren't in the wrong.
Except that probably won't solve anything. You'll just be a quivering mess.
The thing is, it's okay to be wrong. It's also okay to think that someone else is more wrong than you and to justify your actions that way. It's okay if you just don't care if you're wrong.
In the situation I've described above, the friend could probably solve it by explaining their situation upfront. Or you could explain your situation up front and give them a chance to explain theirs.
Mostly, you just need to realise that you're probably wrong and make the most of times when you might be right.