Click on the Smart Filter mask and press Command+I (PC: Control+I) to invert the mask and fill it with black, hiding the effects of the Unsharp Mask Smart Filter.
Use white as the Foreground color paint over the eyes, teeth, and lips to allow the sharpening to appear.
If the subject has lots of hair (as in this example), make a rough selection of the hair with the lasso tool.
Click on the Refine Edges button in the Options Bar to tweak the selection.
Here I played with various settings to get a softer-edged selection.
Once you’re happy with the selection of the hair, fill the selection with white to reveal the effects of the Unsharp Mask Smart Filter.
Here’s where Smart Filters really shine. Now you’ve done all this work, saved the document, and closed it. When you reopen the image later and decide that maybe the Surface Blur was a little too strong, it’s a simple fix (unlike previous versions of Photoshop—you’d be out of luck). Just double-click on the name of the Smart Filter you want to edit and the filter dialog box reopens with the settings you used.
Change the settings, click OK, and you’re done!
Here are the before and after images of your retouching process:
Of course, the second image should be called "current" instead of "after" because "after" suggests that it is your final version. Thanks to Smart Filters, you can always go back and change the "after" until you’re happy.