Trim toenails straight across to your size just in-front of the end with the nail sulcus. Usually do not spherical from the corners as this could cause ingrown toenails. It starts off from the perimeters on the nails and finally requires the nail plate, producing it to become brittle, thickened, https://www.theorthopaedicandpainpractice.com/what-is-an-ingrown-toenail/