Do it out of love.  Do you feel put upon by a request?  Can you say yes anyway?  What if you did it for love?  For the sheer Joy of serving.  Even if the other is appreciative, that is not the reason to say yes.  You say yes, for you may not know how far and wide the impulse of love will spread when you do a thing not because you have anything to gain or because it is an obligation, but because you are Love in expression, and you are allowing your true Self to say hello.  Hello, dear one, you are so very loved.