If there is a key to self-publishing success, I think it would be hand selling your copies. Think about this for a minute. People are more likely to remember you and your book if they met you, shook your hand, talked to you for a little bit. Then, if something should come of your work and you happen to be picked up by a publisher, they are able to look their friends in the eye and say, "Hey! I met that person. They gave me one of their first copies. Signed it too."
While I am not a strong fan of James Redfield's The Celestine Prophecy, I am impressed with his go-getter attitude. He started hand selling his book out of the trunk of his car.
Below is a video of how his writing career took off.