First thing, I zoom in and clone stamp "imperfections" away on a duplicate layer. If I'm 100% happy - I merge and move on.
The very first action I run, and one I would recommend buying just because it's basic and time consuming to create, is a skin re-touch action. Once I've run the action I just take the brush and paint over the face to smooth out skin. Then I adjust the opacity of the layer to a level that looks good and believable - these aren't fashion models in a commercial magazine and to make real people look like that is fake and amateurish, I think.
Then I run a Hair and Eye Highlighter action and paint over the highlights in the hair to make them stand out a bit more, as well as the irises of the eyes. This is usually the time I would fix flyaways as well, but this picture didn't need any such hair touch-ups.
Next, I usually whiten the teeth using a pre-programmed action as well, but here's a really easy way to do it. Zoom in really close and lasso the teeth. Then, using Hue/Saturation > yellows - I de-saturate in order to whiten the them, and lighten them to add a bit of brightness.
Last but not least, I punch up the contrast a bit, boost the saturation a bit more, and maybe adjust the curves a touch. Then save!
Thanks for having me.