This is wrt to India. Before modern nail trimmers, there was something called a “Noroon” which was a high carbon steel forged tool. It was made of the same metal as a straight edge or scalpel, and came in usually two different sizes : one for toe nails and one for finger nails. Most people would have the barber trim their nails.
It was like a small inclined wedge about the width of a spoon handle. This video shows a guy trying to imitate it, but he’s not that good.
I use a clipper on my fingernails and a small pair of dikes on my toenails. My big toenails are a little too big for the curving clippers and my small toenails curl over the end of my toes. Except for the little toenails. They curve up. They’re small enough that they can be clipped with nearly anything with a good grip.
You mean my mother wasn’t correct when she said that they’d inflame my appendix and that when it was removed the doctors would find that it was packed with crescents of fingernails?
I am sort of like that, I hate rough edges and hangnails, and keep a glass nail file and set of clippers on my desk and in my messenger bag for nail care.
Actually a clam shell is just rough enough to use as a nail file, and there is an Amazonian fish that the scales were used as nail files.
I figure that people used knives or equivalent to rough trim, and then something abrasive to smooth. Even a chip of flint and a bit of sandstone would work out.