As Molly suggested, there are many, many ways to add additional depth and interest to an image.
But there are also many ways of adding disinterest to an image.If you take away too much texture in skin for instance you take away the character in it.It just simply will not look real and your image will look faked.
After all the whole idea of your models is to make them look beautiful yet real correct?
By using the word "real" i am referring to not being shopped.

Simply put .....
sometimes you have to take away from an image what you have added to make it look better.