Dirty, ragged fingernails do not give the best impression. Part of standard grooming is to maintain fingernails, toenails and cuticles. Cleaning the nails from dirt and debris is an indispensable part of that. If you work around messy materials, or enjoy gardening or similar activities, it is necessary to learn how to keep dirt out of your nails. It is way easier to prevent getting nails dirty and grimy than spending the time having to clean them extensively.
Trim your nails. Dirt accumulates faster when you have long nails. Use a standard nail clipper. Clip straight across the top of the nails. Cut them to just about the tip of your finger. Use the clippers to trim the sharp corners.
Hold a bar of soap under water and get it thoroughly wet. Any type of bar soap is suitable. Run your nails over the surface of the soap. Dig your nails in a bit so that the soap builds up underneath the nails.
Wear gloves. Thin, latex gloves will keep dirt out of your nails. Another option is cloth gloves used in gardening. Put on the gloves and make sure that they fit well so that they will keep out dirt.