I achieve that look, or my take on it, with a mixture of using the healing brush and the clone tool. Most cosmetic blemishes and uneveness can be fixed by that. The trick is to copy acceptable skin texture from other areas. Skin tonality can be changed using adjustment layers, I prefer working in Curves. There's also a little secret called Diffusion Glow, which can be applied to a duplicate layer and masked into problem areas. It does have a specific look though. The majority of models, I find, have acceptable skin unless at reasonable close ups. The hardest problem for me to deal with is porous faces lit by harsh light. The key to these problems is patience.
Depending on your comfort level with the software, you shouldn't really be spending too much time on skin. I find that the more I worked on practice shots, the faster I got. It seems that the less you play around and the more focused you are, the better it is in terms of time consumption.
But, I'm not sure of your level of experise, so I'll leave it at that. Glad I could be of any help.
