What are some unwritten rules of life?

1. Maintain civil respect. When you go out to travel somewhere or online on any social media platform, remember that you represent the people of your country. Any post or comment you make is not only your identity but also the identity of the people of your country. So try to maintain that respect.

Do not interrupt someone when he is speaking. After his speech is complete, keep yours. We South Asians have this habit of watching TV debates. Let's all change that.
Learn to give back. If you ever take something from someone, try to return it at the same time or when it is in good condition.
Learn to give personal space. Everyone has their own personal space or a boundary of their own preferences. Try not to cross that line.
Don't talk about someone behind their back. It destroys trust and confidence.
Do not think of powerful people as having divine powers. We often see politicians, movie stars in this way. But in the Holy Gita, God says, "If you want to go somewhere, try to be on time. If you value other people's time, they will feel responsible towards you."
Never dirty public place. Keep a place or thing clean and usable after use.
Help whenever you can, even in small ways. Even small benefits can have a big impact.
Learn to improve diction and speaking style. Having the right diction and style of speech when you speak to someone will give them a good impression of you.