How to give to worthy causes?
It is HARDDDDD to give away YOUR money. It almost HURTS for some of us!! [A famous gvir once asked a Rebbe how much he should give to a certain cause. The Rebbe said "A sum that hurts". The gvir said "10 dollars hurts...." And this guy has his name on buildings. זצ"ל!!]
But it is not your money. Just like your body is not YOUR body.
It is Hashem's money that he deposited with you to increase good in the world. Giving away the money of Someone who owns all the money in the world is EASY!!!!!!!!!!!!!!!!!!