On the making side I just love the smell of of the leather and how it feels to the touch. All of that aside I'm with jordon"My favorite part is when someone says " That is just what I need, How much?" And we make the exchange, my time and talent for their money! " but even more so when someone gets in contact with me and says they love what i have made for them(either comercially or Just a gift).
I made a set of tooled bracers for a friend(back in my medievial days) for a wedding gift and everytime i see him he brings up how much he loves them.
chris