Be good

And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him - col.3.17

For everything or anything you do for anyone, never do it with the condition of "getting something in return" or in the spirit of "keeping up with your good works". Be good, because it is the right thing to do. Be good because God requires that. Be good because someone else needs it.