Well first of all it's important to know that the Dove people are being a little bit deceptive with the 'editing' process to make people think that it's all about makeup and computers, that it's through computer magic that ordinary women are made to look extraordinary.
This really isn't so true. If you are referring to the video where they show the transformation of the girl, it's important to note that while the girl LOOKS quite average before the transformation- I assure you she is not. If she is not already a professional model, she certainly already has the facial qualities that she would require to be a successful working model. These days things like clear skin are not as important as strong, defined bone structure, even features , nice nose and a squarish shape. This woman, although 'ordinary looking' is already far 'more beautiful' than the 'average' woman.
After that, its about lighting. The lighting is chosen to be extremely flattering and to accent her natural shapes. As a note, the light used in the video (a fluorescent ring light) the final image is shot with a different lighting configuration and flash. Which changes dramatically what she looks like.
The point? It's not all computer magic. Makeup helps. A great deal. Computer retouching magic adds the 'special touch' with things like elongating the neck and so on. But the basics: Good lighting and a beautiful woman never change in fashion. But if your working with 'less' than superstar models, then just be sure to light it nicely. Generally, 'on camera flash' isn't going to be very flattering.
Dennison Bertram, Czech Fashion Photographer