I have been trying to add some type of red polish to her nails and its driving nuts. Need some advice on how to add fingernail polish or something that is similar it? Any other pointers are welcome as well. Thanks!

I've fixed jagged nails/nail paint by cloning.
maybe use a brush on low opacity with colour of choice and paint over them?

I just paint the color on a new layer (if it's very hi-res, I'll use the pen tool to create the nails, if not, I don't bother), then add the gloss with white on new layers.

There's bound to be PS tutorials out there if you expand your search to just generally glossy things.

Stuff like this  - which is a lot like painting - really demands that you pre-visualize. If I don't know what I want to see, I can really spin my wheels. Once I look at some reference images (google shiny nails), it all falls together.



These (above) were painted (with the paint brush) over stubby unpolished nails. The photographer didn't ask me to, I just couldn't stand looking at them anymore while I retouched the rest of the picture! Use layers, blur some, sharpen some, but know what you want it to look like before you start.