There is no best way. Each one can do based on their own financial capacity, convenience, skill and time availability. You can sponsor education for underprivileged children, contribute to NGOs working for that, can teach them free if you have skill and time and so on. There is no way that is better or inferior to other. I sponsor education for two children at SOS, provide the year around books and stationery items for my household helper's child and give remedial sessions to special need children of poor family at low cost or free. That is my way of contribution that suits my capacity and convenience.