1.) Nail shape is important because it helps to showcase your style and personality. It's been said for many years by nail gurus around the world that your nail shape can tell a lot about the type of person you are. Your choice in nail shape can tell others whether you are bold and daring, or reserved and laid-back.
2.) If you have medium or long nails, oval, almond, and coffin shapes will suit you best. Use elongating nail shapes, such as almond, coffin, and oval, to lengthen and slenderize short and wide fingers. Ladies with fingers that are naturally long and slim should choose a square nail shape for a flattering effect.
Or
Round shape
because the shape is most shapes of the nail and it is easy to design and you won't get wounds because of its edge unlike square shape in just one wrong move you'll get hurt because of it