I would go so far as to say, even better than doing something good and 'caring' for someone (you should do that anyways) is to get in debt to someone. Maybe not financial debt, but ask other people for a favor, or help. Psychologically, the person is then invested in you to repay that debt in the future. After all Kennedy said "ask not what your country can do for you, ask what you can do for your country", thus putting the country in debt to its citizens, and his popularity soared.
This is about you helping strangers, or friends of friends. Moving, cooking dinner, helping with a legal problem, helping them with their exams, letting them borrow your rice cooker over the weekend, helping them with their birthday party, inviting them for a drink, volunteering to look after their dog and so on.
It's not about helping everyone, it's about helping the people you care about (supposedly, your friends)