I give to 6 different charities on a monthly basis. Charities that mean something to me, that I hand picked. It's a significant amount but funny thing is, I don't even miss it and feel that I get more in return, somehow. My husband (who is very spiritual) truly believes that when you give, you get back ten fold. He will give a Girl Scout money for cookies, but not take the cookies!
At my job, if a charity or church buys something from us, I will often pay for it (which is how one of the charities got on my list).
Once, hubby and I were eating out and I noticed an older couple with, I assume, their grandson. They prayed before they ate, something you don't see often, and for some reason, it just really touched me. When we went to pay for our meal, I asked their waitress for their bill and payed it.
Acts of kindness, big or small, are beneficial for the giver and the receiver. But, I actually think it benefits the giver the most, emotionally.