The questions ‘whom?, when? and how?’ are very important when you offer something to somebody in your day to day life – whether it is a an act of mercy or a material support. There is no textbook for you to study and there is no one guru who can teach you this effectively. Since it is the case of day to day life, and your response has to occur as a reflex in most cases, you may not get time to plan it as if you were a management professional. Therefore, the only way before you is to live among people as a sensible person, observe things carefully and learn things by doing – it is the real life skills. The earlier you start this in your life the more victorious you will be. Here we find the overriding importance of fostering life skills from the early childhood itself.
Practice it and make it a habit. Then the nature will make it sustainable by triggering necessary genetic engineering!