That is still relatively easy to cut your finger on.

I don't know that there's a correct way, really. You would probably have to take the time to file or sand the edges. Which kind of levels the playing field with the cable lacing option really in terms of time spent.

Trimming the excess flush with the head is the correct way. It's not perfect, but it is much safer than leaving a sharp stub sticking out.

The absolute worst thing is to trim at any angle other than 90 degrees -- doing that creates a small knife.