During the course of the 4-part episode, when Aang is on the Lion Turtle certain sequences show him barefoot before cutting to him wearing his shoes and back to him being barefoot, all in the same scene.
Toph sandbends a perfect model of Ba Sing Se complete with the Earth King and his bear, but since she's blind, there's no way she would know what the town's layout or anyone in it looks like to make a 3D sand model of them.