I've never given much thought to nail/hand care. I keep my nails short and generally don't use lotion, because it transfers to the keytops.
I'm also prone to hangnails, and every once in a rare while my fingertips feel bruised if I practice vigorously for an extended time after trimming my nails.
I'm so used to all of this, it's never until now occurred to me to question it. But then I read this, regarding guitar playing:
Shorten your nails as much by possible, but not by cutting. The problem with cutting them very short is that the tool compresses the fingernail and pulls it away from the skin. That causes the separation and pain. You should cut your nails only to a comfortable point, and then from there continue to shorten them by filing with a diamond file. (SOURCE: SE MP&T)
I cut my nails will a clipper. Are manicure scissors better? Should I file them? With a certain type of file? Should I go all out and get manicures? Should I be treating (or preventing) hangnails is some way? Is there some advantage or disadvantage to more or less dry skin?
What should pianists consider in caring for our hands and nails? What kind of impact, if any, do the care techniques chosen have on our hands, nails, and piano playing?