The original optimised image looks fine to me and I would not usually do any more work than has already been done. As my PS skills are self-taught and I have not had any reason to attempt more intricate work I took quite a few hours before I actually even managed to create a layer mask to work on! Unless any of my images were exceptional I cannot see me performing this sort of manipulation on a regular basis---far too time consuming , I would rather be shooting. However I did enjoy the exercise and became quite absorbed. To make my subject ( Caitlin ) stand out more I increased the vibrance and brightness , made a curves adjustment to increase the contrast, and finally decreased the yellow saturation very slightly to alter her skin tones. Have I improved the image? I am quite pleased with the final result , it is brighter with bolder brighter colour, but that is my opinion, not everybody would agree, its my personal interpretation.
I made a duplicate layer and used the magnetic lasso tool to select Caitlin saving the selection as a mask. I then created several adjustment layers.