Nail polish can be aggressive.Let your nails breathe every two weeks with no nail polish. A layer of strengthener before the polish will act as a protective base.
Moisturise the cuticles with protein oil to avoid pesky skin that sometimes appears around the nail.
Wash your hands, preferably with cold water and always dry them well.
Protect your hands with gloves if you are doing something that can cause damage or you are using a chemical product. Exfoliate them every month to restore elasticity and softness.
Try to follow a balanced diet, rich in fruit and vegetables and, above all, get the amount of sleep that your body and mind need.