1. Don’t call someone more than twice continuously. If they don’t pick up your call, presume they have something important to attend to.
2. Return money that you have borrowed even before the person who loaned it to you remembers or asks for it. It shows your integrity and character. The same goes for umbrellas, pens, and lunch boxes.
3. Never order the expensive dish on the menu when someone is treating you to lunch or dinner.
4. Don’t ask awkward questions like ‘Oh, so you aren’t married yet?’ Or ‘Don’t you have kids?’ Or ‘Why haven't you bought a house?’ Or ‘Why haven't you bought a car?’ For God’s sake, it isn’t your problem.
5. Always open the door for the person coming behind you. It doesn’t matter if it is a guy or a girl, senior or junior. You don’t grow small by treating someone well in public.
6. If you take a taxi with a friend and he/she pays now, try paying next time.
7. Respect different shades of opinions. Remember, what may seem like 6 to you might appear as 9 to someone else. Besides, a second opinion is good for an alternative.
8. Never interrupt people while they are talking. Allow them to pour it out. As they say, hear them all and filter them all.
9. If you tease someone, and they don’t seem to enjoy it, stop it and never do it again. It encourages one to do more and shows how appreciative you are.
10. Say “thank you” when someone is helping you.
11. Praise publicly. Criticize privately.
12. There’s almost never a reason to comment on someone’s weight. Just say, “You look fantastic.” If they want to talk about losing weight, they will.
13. When someone shows you a photo on their phone, don’t swipe left or right. You never know what’s next.
14. If a colleague tells you they have a doctor's appointment, don’t ask what it’s for, just say "I hope you’re okay." Don’t put them in the uncomfortable position of having to tell you their personal illness. If they want you to know, they'll do so without your inquisitiveness.
15. Treat the cleaner with the same respect as the CEO. Nobody is impressed by how rudely you treat someone below you, but people will notice if you treat them with respect.
16. If a person is speaking directly to you, staring at your phone is rude.
17. Never give advice until you’re asked.
18. When meeting someone after a long time, unless they want to talk about it, don’t ask them their age or salary.
19. Mind your business unless anything involves you directly - just stay out of it.
20. Remove your sunglasses if you are talking to anyone in the street. It is a sign of respect. Moreover, eye contact is as important as your speech.
21. Never talk about your riches in the midst of the poor. Similarly, don't talk about your children in the midst of the barren.
22. After reading a good message, consider saying "Thanks for the message."

I still haven't even figured out how to keep and maintain it.