Nails should be always dry while filing because wet nails tend to split more easily.
Make a proper angle of 45 degree to bottom side of the nails tips while filing your nails. Do not hold in the perpendicular position to the nail tip.
It is important to file your nails so that they are even in length and are well shaped.
Filing should be done in one direction only and not in a sawing motion as this could cause weak nails to split.
Use a nail clipper to clip the bigger nail portions to get the basic nail shape of square shape or oval shape. Don’t clip in the center of the nail, but use two cuts, one on each side of the nail. Clipping the nail makes your filing process easier.