The beauty of such corrections is that they can be applied to any image and changed to the point that people can't believe what you started with. Let's dive in and see how to really make those images sing.
Note: The corrections I will discuss here are described in CMYK because anything being printed on paper by a printing press will be of a four-color process, with the occasional special Pantone color. The basic principal of a correction can also be applied in RGB. When I speak of four-color process, to clarify, some ink jet type printers are called RGB devices, but for the most part this means that they like to receive an RGB file. They will then use their internal conversion process to convert the file to CMYK, as the inks used in these printers are CMYK. Some printers use additional ink colors as well to enhance the image.