It’s not useful to cut a V in the middle of the toenail, this won’t reduce the chances of your toenail becoming ingrown. It’s important to cut your toenail straight across and perhaps use a file to smooth any rough edges and corners. Always avoid digging down the sides or cutting them down the sides as this can cause ingrowing toenails.
Always try to use a toenail clipper as opposed to a fingernail clipper. This way you should be able to achieve a nice straight edge all the way to the end.