My Grandson entered a auction on ebay to help the flood victims of LA and MS.
He baked cookies with all proceeds to benefit the American Red Cross. What made this a unique auction is that my grandson at the time was 6 years old and even at this age, he knew the importance of helping others in need, and wanted to help. No it was not my idea but his own.
He was too young to donate money per say, but he loved to make cookies. I took a picture of him baking the cookies and had that in the listing, this way people interested in bidding on these cookies, could see this was genuine.
He assisted with the listing, adding input on what he was doing and why. The outpouring of support for this charity was immense do to the fact that a child was willing to give of himself and help others with no benefit to himself.
I would suggest to put the reason if personal in the listing, make it unique and most of all truthful.