I put a sign by the driveway, and neighbors stop in to buy them. I also sell to friends in the city when I go to visit or go to any gathering. I let people know if I'll be bringing eggs, I almost always sell all I bring. I used to sell them at work, too, when I was still working. I just let people know I had chickens, and they started asking if I sold eggs. I took eggs in with me a couple times a week, I very seldom had any left over.
Rarely, I build up excess, and when that happens, I take them to the local battered women's shelter, and donate them. I get a tax deduction, and the women and kids at the shelter get farm fresh eggs. Food banks and missions are usually happy to get extras, too. I take extra garden produce to the shelter, too, when I have it.