For pretty savvy girls

Strengthen nails

Never use your nails as tools – scraping things off, opening tabs off cans, etc.
Wear rubber gloves if you are ever working with chemicals
Keep your nails polished, even if it’s only a clear coat. You can try nail-strengthening formulas, but even basic versions thicken the nail lessening the chance of a split
Don’t overbuff your nails, you don’t want to take off too much of the top layer.
When filing, always go in the same direction, don’t saw back and forth
Take care of your cuticles. When applying hand moisturizer, work it into the cuticle and nail itself
Eat biotin-rich foods or take a supplement. Examples are eggs (it’s in the yolk, so egg whites don’t count), nuts, and wheat bran