My favorite smile of my son's is his closed-lip, I've-got-a-secret smile. Sadly, this was the best photo I had of it:
It's underexposed, it's too blue, his cheeks are red and blotchy, and that drop of snot looks terrible.
I upped the exposure, minimized the shadows, and brought in more white until I had the color/exposure/light that looked good to me. Then I used the brush tool to remove some spots. I smoothed his skin just a tiny bit, and then brought up the exposure in his eyes. I could do a bit more work to get the snot out of his nostril, but I was having problems getting the spot correction tool to work as I wanted it to.