I believe that when a person does something for someone, I believe you should do it as unto the Lord. Firstly, your motives will be right and secondly, you won't have expectations of a pat on the back. And when you do something as unto the Lord, He rewards you (much better than a pat on the back!)
I also believe that when you bless someone and the recipient does not know who blessed them, God gets the glory. Is that not what generosity and giving should do? Bring glory to God?
Matt 6 v 3-4: But when you do a charitable deed, do not let your left hand know what your right hand is doing, that your charitable deed may be in secret: and your Father who sees in secret will Himself reward you openly.
Another aspect of giving is how to give - give with joy, give with love, give because it is such a blessing to be the giver.
2 Corinth 9 v 7: So let each one give as he purposes in his heart, not grudgingly or of necessity: for God loves a cheerful giver.
There is a natural law at play when giving. You have seen many generous unsaved people giving generously and they seem to get wealthier. Add to that God's spiritual law of giving which I believe is:
2 Corinth 9 v 6: He who sows sparingly will also reap sparingly, and he who sows bountifully will also reap bountifully.
Therefore - you cannot outgive God
If you are blessed, God wants you to be a blessing in return. Be someone who is used of God to bless. You could be blessed financially, or with time, or with kind words, or a talent that can bless. "Pay it forward" as a popular movie says.
My encouragement to you is to start practicing blessing others, a random act of kindness for example, do it as unto the Lord, do it in secret (there is great joy in that) and do it often. You will be blessed out of your socks!
I'm linking with Shanda at A Pause of the Path