The phrase or concept of "putting yourself in someone else's shoes" is a constant phrase and theme the novel. When Miss Caroline tries to give Walter a quarter for lunch, she doesn't consider that he might refuse because of shame that he can not repay her. In other words, Miss Caroline doesn't put herself in Walter's shoes (think of things from his perspective). Scout also realizes that she didn't consider Miss Caroline's point of view and that this was an honest mistake:
Atticus said I had learned many things today, and Miss Caroline had learned several things herself. She had learned not to hand something to a Cunningham, for one thing, but if Walter and I had put ourselves in her shoes we’d have seen it was an honest mistake on her part. We could not expect her to learn all Maycomb’s ways in one day, and we could not hold her responsible when she knew no better.
In Chapter 15, Scout intervenes when the mob approaches Atticus to get their hands on Tom. In Chapter 16, Atticus remarks that the children got Walter Cunningham Sr. to think in his (Atticus') shoes:
Hmp, maybe we need a police force of children… you children last night made Walter Cunningham stand in my shoes for a minute.
This lesson, primarily provided by Atticus, even applies to Bob Ewell. When Bob spits on Atticus, he chooses not to retaliate. As usual, Atticus considers the perspective of others and this allows him to make ethical decisions:
Jem, see if you can stand in Bob Ewell’s shoes a minute. I destroyed his last shred of credibility at that trial, if he had any to begin with. The man had to have some kind of comeback, his kind always does. So if spitting in my face and threatening me saved Mayella Ewell one extra beating, that’s something I’ll gladly take.
In the final chapter, Scout realizes that Atticus was right; that you can never really know a person until you stand in their shoes and consider things from their perspective.