Is Atticus's advice to put yourself into someone else's shoes really the most effective way to get along with others? Is it a feasible way to act?

You have to love Atticus. He has got to be one of my favorite fictional characters. Sometimes I pretend that he was real, it makes me feel a little better about the world. His advice is wonderful but not always easy. If you truly put yourself in another's shoes, you have to be willing to sacrifice something. I mean that empathizing with someone else leaves you vulnerable. It also forces you to examine your own motivations and emotions. This is not an easy thing to do. Most people do not want to discover they are in error or leave themselves open to scrutiny. Atticus certainly lived this way. He put his life on the line for his beliefs. This is why we discover that Mrs. Dubose in not in fact just a mean old cow. I think it is feasible to feel another person's pain but you have to be ready to feel vulnerable yourself.

Yes, Atticus' advice is effective; it's a platform, a way to live. This small bit of moral advice governs the way Scout develops throughout the novel. Atticus lives this principle in his own life and in his work; his advice to his daughter is more than advice, it's wisdom. She may not have understood its complete meaning at first, but Atticus knows how to relate to his children.

Scout often struggles to succeed in "putting herself in someone else's shoes, but as the novel progresses we see her practice his advice through her ability to sympathize and understand others around her.

You ask if this is feasible? What could be more feasible than living life trying to understand others rather than judging them? It is important for people to look below the surface and beyond themselves......... shortsightedness breeds ignorance.