Simple, I ask for something small in return - a four-pack of beer, help with my car, dinner, or something like that. I started doing this many years ago, and it

Simple, I ask for something small in return - a four-pack of beer, help with my car, dinner, or something like that. I started doing this many years ago, and it's got rid of the "Hi, I'm a fried of your brother"-type calls, whilst my friends and family have recognised that it's work for me nonetheless. End result: everyone goes home happy :)