In the realm of personal hygiene, your fingernails should rest somewhere between your breath and body odor. Nothing says "crude caveman" more than dirty, gnarled nails or jagged, bloody cuticles.
During your shower, push back your cuticles (the skin-like tissue covering the base of the nail) using the back of your thumbnail. This will keep your nails looking clean and your cuticles from getting caught on something and ripping.
After showering, your nails are soft and easier to trim with a pair of nail clippers. We recommend the "Ultra-Slim Stainless Steel Nail Clipper" by the German knife company, Zwilling. Just don't cut the nail shorter than the tip of the finger.
Never bite or pull off hangnails. Doing so will rip your hand's living tissue. Instead, use scissors to clip hangnails, leaving a small angle outward.
Filing the nails isn't always necessary, but is a practical way of finishing them to a smooth edge. An emory board like Mom uses would work, but you should really find one with a finer grit. Did you know they come in grades like sandpaper? We like Tweezerman's pocket file—with a built-in nail cleaner, long-lasting ceramic stone and travel-handy switchblade design, you really get your money's worth.
The occasional manicure by a professional will give you nice, even nails that can be easily maintained. But if the manicurist suggests a polish, ask for a buff instead.
And remember, nails need moisture just like skin. Rub lotion into your nails when moisturizing your hands. A good time for doing this? Right before bed.