Volunteer to do someone you know a favor. It doesn't even have to be someone you know very well. If fact, offering your services to a person you don't know well, but would like to know better, is an ideal way to begin to deepen a friendship.
Think carefully about someone you know who would be delighted if you offered to help him or her with something, who would really appreciate and value your help, and who would thank you sincerely. Go ahead, call her up. Or better yet, show up at her door and say, "Okay, my friend, you got me for the next three hours. What'ya got to do?"
If you turn out to be wrong, and the person you chose ran your derriere ragged and didn't so much as thank you for it, don't feel bad. Simply congratulate yourself for extending your services and know that your generosity will come back to you some other time.
— Alan Epstein in How to Be Happier Day by Day