As social beings, we are obligated to follow some principles, values. This is something that distinguishes us from the other animals.
I have a set of values that I always respect. They help me to get peaceful sleep at night.
A trivial example is when you find a cash bill on the ground. The easiest thing to do would be to pick it up and put it in your wallet. Instead, you can try to wait closeby for several minutes. If you see a person looking for something, probably that's the person that lost the bill. Give it back to them.
You may also find yourself having an opportunity to level up your career at work, but this would put somebody else in a risky position. Don't be selfish. Talk to them. Try to have broad understanding of the whole situation. Care about it. If you still get the position: congratulations! If not, you might think you have lost an opportunity, but that opportunity wasn't there in the first place.
Don't cheat on your partner. Don't treat others badly without a reason. Don't act like a child.
Think about any behaviour that annoys you. Think about what somebody does when they behave like that. Do your best to not do the same.
Do things that people expect to do themselves. Surprise them. It's simple. You can pay for a coffee to a friend without any particular reason. You are not going to be bankrupt for that. If somebody is struggling with a situation, support them. You can dedicate some of your time to this, your priorities can wait.
Why is a person arguing with you? Don't they have better ways to spend their time? Many people argue because they want to vent. They don't have anything against you. They are living a bad moment in the day or in their life. Stay calm and put yourself on the other side. What do you feel? What do you want to say? You will probably be arguing as well in that situation.
This is the hardest for me. In a situation where something is on the table, say somebody has to do a big effort in order to fulfill one of your tasks. It's their job, but it's annoying and feels unnecessary to them. Be brave and do it yourself. Try, at least. Show that you are aware of the effort that is needed and that you are willing to do it yourself. Mean it. Most of the times this will actually result in you not doing the task. It will result in the other person doing the task with less effort. They will feel that they are really helping you with their work.