Oil and strengthen. Dryness is the “common culprit” behind breaking and peeling, so keep your nails hydrated. A hand cream will work, “but cuticle oil is better,” especially for manicured nails, because the oil penetrates polish. If your nails tend to peel or split, consider using a calcium- or protein-based nail strengthener.
Use a fine-grain file. Metal files or coarse boards “fray the nail’s edge, causing nails to snag and peel.” Choose a board with a fine grit instead, and avoid overfiling the sides of each nail, because the nails’ sides provide structural support.
Protect. Resist the temptation to peel away old polish—small parts of your nail plate will get pulled off in the process, leading to more splitting. And stop using your nails to open boxes or scrape dishes. Repeated stress eventually leads to breakage.
Source: Good Housekeeping