Everything starts out as a concept, including shoes. In the beginning, they're designed on paper, but then they're put on something called a "last." Think of it like a shoe blank. It's blank white, but it's a three-dimensional model of a shoe. This is how the designers get a more accurate depiction of their could-be shoe.
Once the design is finalized, the fabric is cut and shaped to the specifications required for the shoe. Once the basic shapes have been cut, a machine called a skiving machine thins the edges so the various pieces are easier to sew together.
The top half of the shoe is called "the upper." The pieces of the upper are sewn together first, then flattened out to give it a smooth finish. At this point, the upper is still a flat, almost U-shaped area of material. Along the inside of the "U," a leather or plastic edge is sewn on to give it a decorative look and hide any unfinished edges. Then the upper is placed back onto the last, with a layer of lining underneath it. An insole is glued underneath them, and then the lining is glued to the upper.
Machines smooth out the excess material hanging over the insole by tucking it back in underneath the shoe. The bottom of the shoe is smoothed out and then a sole is placed on it to cover up any unsightly extras, and to make the shoe comfortable and durable. Excess glue is removed, laces are put in, the blank is taken out, and the shoe is finished.